BMJ Open€¦ · For peer review only 16 15. Kehlet M, Schroeder T, Tønnesen H. The Gold Standard...

For peer review only

Effectiveness of the Gold Standard Programme Compared to Other Smoking Cessation Interventions in Denmark: A

Cohort Study

Journal: BMJ Open

Manuscript ID bmjopen-2016-013553

Article Type: Research

Date Submitted by the Author: 21-Jul-2016

Complete List of Authors: Rasmussen, Mette; Bispebjerg & Frederiksberg Hospital, WHO-CC Fernandez, Esteve; Catalan Institute of Oncology, Cancer Prevention and Control

Tønnesen, Hanne; Health Sciences, Lund University, Clinical Health Promotion Centre; Bispebjerg and Frederiksberg University Hospital, WHO-CC, Clinical Health Promotion Centre

<b>Primary Subject Heading</b>:

Smoking and tobacco

Secondary Subject Heading: Addiction, Public health, Epidemiology

Keywords: smoking cessation, denmark, abstinence, cessation program, effectiveness, nationwide database

For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml

BMJ Open on O

ctober 26, 2020 by guest. Protected by copyright.

http://bmjopen.bm

j.com/

BM

J Open: first published as 10.1136/bm

jopen-2016-013553 on 27 February 2017. D

ownloaded from

http://bmjopen.bmj.com/


1

Effectiveness of the Gold Standard Programme Compared to Other Smoking Cessation

Interventions in Denmark: A Cohort Study

Mette Rasmussen, Esteve Fernández, Hanne Tønnesen

Clinical Health Promotion Centre, Bispebjerg and Frederiksberg Hospital, DK-2000, Denmark

Mette Rasmussen

PhD fellow

Hanne Tønnesen

Director

Tobacco Control Unit, Institut Català d’Oncologia (ICO-IDIBELL), L’Hospitalet, ES-08908, Spain

Esteve Fernández

Director

Department of Clinical Sciences, School of Medicine, Universitat de Barcelona, ES-08908, Spain

Esteve Fernández

Associate Professor

Health Science, University of Southern Denmark, DK-5230, Denmark

Hanne Tønnesen

Professor

Clinical Health Promotion Centre, Department of Health Sciences, Lund University, SE-221 00, Sweden

Hanne Tønnesen

Professor

Correspondance to Mette Rasmussen e-mail: [email protected]

Page 1 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960

on October 26, 2020 by guest. P

rotected by copyright.http://bm

jopen.bmj.com

/B

MJ O

pen: first published as 10.1136/bmjopen-2016-013553 on 27 F

ebruary 2017. Dow

nloaded from



2

Abstract

Objectives: We compared the effectiveness of the Gold Standard Programme (GSP) and other

face-to-face smoking cessation programmes in Denmark after implementation in real-life and

identified factors associated with successful quitting.

Design: Cohort study.

Setting: >300 smoking cessation clinics from different settings reported data from 2001–

2013.

Participants: 82,431 patients were registered. Smokers ≥15 years old, attending a programme

with planned follow-up was included. Smokers not wanting further contact, intentionally not

followed up and without information about the intervention they received were excluded.

46,287 smokers were included.

Interventions: Different real-life smoking cessation interventions.

Main outcome: Self-reported continuous abstinence for 6 months, follow-up rate 74%.

Results: Over all 33% (11,184) were continuously abstinent after 6 months, 24% when non-

respondents were considered smokers.

Women were less likely to stay abstinent; 0.83 (0.79 to 0.88). Short interventions were more

effective to men. After adjusting for confounders GSP was the only intervention with a

significant result across sex, increasing the odds of abstinence by 70% for men and 35% for

women. Especially compliance, and to a minor degree lightly smoking, older age, and not

being a disadvantaged smoker were associated with a positive outcome for both sexes.

Compliance increased the odds of abstinence more than 3.5 fold.

Conclusions: Over time Danish smoking cessation interventions have been effective in real-life.

Compliance is the main predictor of successful quitting. Interestingly, short programmes seem

to have relatively high effect among men, but the absolute numbers are very small. Only the

comprehensive GSP works across sex.

Page 2 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



3

Strengths and limitations of this study

• This study was based on a large cohort containing smokers from all regions and

settings in Denmark; 46,287 smokers were included in the study, and the follow-up

rate was high (74%).

• The study was based on routinely collected health data with a high completeness and

precision, and the implications was considered sparse, since the research question was

in line with the purpose of the database.

• Confounding was carefully considered and adjusted for, but we cannot exclude the

possibility of residual confounding from other potential confounders such as genetic

predisposition, co-morbidities, competing addictions and lifestyle factors not included

due to lack of information.

• It is a limitation that the results were based on self-reporting since patients are likely

to overestimate their success; we assumed that the overestimation was evenly

distributed hence, the groups were comparable in spite of the possibility of slightly

overestimated quit rates.

• Due to different cultural traditions, smoking habits, and socio-economic conditions,

generalisation should be considered carefully.

Page 3 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



4

Introduction Tobacco is the most damaging and preventable lifestyle factor for public health globally and

nationally1,2. The harmful effects are well documented3. Globally WHO estimates that

approximately 6 million people die of smoking-related diseases yearly1. Many countries,

including Denmark, have introduced restrictive laws and strategies to reduce smoking4. More

than 12,800 people in Denmark die as a consequence of smoking annually, corresponding to 1

in 4 deaths4.

In the last 15–20 years, many initiatives have been launched to help smokers quit. Smoking

cessation programmes are one of many initiatives. Additionally, tobacco control and policy

measures have been implemented including smoking bans, higher tobacco taxes, and

restrictions on sales and advertising. Recently, Denmark signed WHO's goal that smoking

should be reduced by 30% in 20255, and specific regions work towards implementing tobacco

endgame6. Furthermore, there are many other offers to help smokers quit, such as Quit-lines,

national campaigns, training materials, and more recently, aids based on information

technology tools. These actions contribute overall to a general change in the smoking climate

and attitudes. In Denmark the smoking prevalence has declined by 0.5–1% per annum during

the last decade. In 2013, 17% of the Danish population over 15 years smoked daily, and an

additional 6% was occasional smokers7.

Since 1995 the comprehensive Gold Standard Programme (GSP) has been routine in Denmark.

GSP has proved to be highly effective and cost-effective, even across subgroups8–13. Apart

from the GSP, other face-to-face methods (e.g. crash courses, health promotion counselling,

alternative treatments and Come & Quit) have been used and evaluated through the national

Danish Smoking Cessation Database (SCDB). The aim was to compare the effectiveness of GSP

and other face-to-face smoking cessation programmes in Denmark implemented in real-life.

The main hypothesis was that the GSP would be the most effective intervention after 6

months. We also aimed to identify factors associated with success in smoking cessation.

Methods

Study design

This cohort study on the national Danish Smoking Cessation Database (SCDB) included

patients treated from 2001–2013 with follow-up till 2014. The SCDB includes approximately

80–90% of all face-to-face interventions in Denmark14. The Danish Data Protection Agency

(2014-41-3370/2000-54-0013) and the Scientific Ethics Committee (H-C-FSP-2010-049)

approved this study and the SCDB.

Setting

During the study >300 smoking cessation clinics reported data from municipal clinics,

pharmacies, hospitals, midwives, primary care facilities, and other private providers. Smokers

could attend smoking cessation interventions free of charge with or without referral.

Approximately 10% attended an intervention at a private provider with payment. From

2001–2005 the proportion was 19%, and from 2006–2012, 4%, probably due to structural

changes made in the Danish healthcare system14.

Page 4 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



5

Intervention

Different real-life smoking cessation interventions were identified and compared from the

data registered in the SCDB (see table 1).

In accordance with guidelines, patients who attended at least 75% of the scheduled meetings

were considered compliant15. For Come & Quit16 (see below) 4 meetings corresponded to

75% of the GSP.

Table 1: Description of the different smoking cessation interventions in this study.

Intervention

Gold Standard Programme

The GSP was the standard smoking

cessation intervention in Denmark.

Training of the counsellors and teaching

materials were developed through the

Danish Cancer Society.

The patient and counsellors decided

whether to attend individual or group

counselling. The first two weeks covered

sessions on ambivalence and motivation,

pros and cons of smoking versus

cessation, and setting a quit date. After

the quit date the last 3 sessions covered

handling of risk situations, withdrawal

symptoms and medical support, relapse

prevention, and how to handle a smoke-free life10,11

.

Come & Quit

This concept was developed to attract smokers who would not frequently visit the smoking cessation clinics. Each

patient had an individual meeting with the counsellor. The concept offered eight meetings of 1½ hours with different

themes in open groups. Each patient could choose how the course was composed and which meetings to attend.

Between meetings patients could receive text messages, e-mails, and/or phone calls according to their individual

wishes16

. Come & Quit was registered in the SCDB from 2011.

Crash Courses

Crash courses consisted of one meeting of approximately 1,5 hr often in a large groups (up to 24 smoker). The meeting

contained information on smoking cessation, the use of nicotine replacement treatment, and further offers to stop

smoking.

Health Promotion Counselling (Brief intervention)

This intervention was based on the five stages of readiness to change. The counselling intended to support the patient

to move on taking into account the stage of change at start. It was also based on elements from short intervention

that have proven effective in the modification of alcohol habits, e.g. personal feedback.

Other

This category contained any other intervention e.g. acupuncture and special concepts. Also interventions where

telephone consultations substituted some of the face-to-face meetings of GSP were registered in this category.

Participants

In 2001–2013, 82,515 smokers were registered in the SCDB after giving informed consent

(see figure 1).

Inclusion criteria: Patients ≥15 years old at the beginning of the programme attending a

smoking cessation programme with planned follow-up.

Page 5 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



6

Exclusion criteria: Patients <15 years; patients not wanting to be contacted after 6 months;

patients intentionally not followed up because the smoking cessation clinic pre-decided not

to; patients without information on which intervention they received.

Thus 46,287 smokers followed up for 6 months were included (figure 1). 26,0% were lost to

follow up because they did not respond or smoking status was missing. The remaining 34,235

patients were included in the outcome analyses. Overall, up to 82,431 patients were included

in the non-respondent analyses.

Figure 1: Flowchart.

Data

Data were reported to the SCDB using standardised questionnaires on smoking history, socio-

demographic characteristics, treatment, and follow-up.

Effectuated from 2006 minor adjustments were made to the questionnaires and follow-up

procedures. No validation of the self-reported smoking status was required. The timeliness for

follow-up was 6 months after the scheduled quit date or secondary the date of course

completion. From 2001–2005 the information was collected by mail or telephone, and at least

one reminder was required. From 2006 and on going the data were collected by telephone

exclusively. After four attempts to reach the patient, of which at least one was in the evening,

the patient was reported as a non-respondent.

Outcomes

Primary outcome:

Continuous abstinence for 6 months, defined as not smoking from the intended quit date (or

last treatment data) to the 6 months follow-up ±1 month.

Other variables

Factors associated with a positive outcome were studied after controlling for intervention,

time of collection, age, disadvantaged patients, heavy smoking, compliance, living with a

smoker, setting, geographic region, programme format, and medication offered for free.

Page 6 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



7

Most variables were collected in categories. Age, daily tobacco consumption (grams/day), and

Fagerström score for nicotine dependency (from 0–10 points)17 were collected as continuous

data. Data were categorised as shown in table 2.

GPS and other interventions were available throughout the study period but crash courses

were only provided before 2006. Finally Come & Quit was recorded from 2011.

Table 2: Characteristics of the included smokers according to type of intervention. Dashes indicate that

the variable was not measured.

GSP Health Promotion

Counselling

Crash Courses Come & Quit Other

n (%) n (%) n (%) n (%) n (%)

Totala 40,651 (100) 140 (100) 183 (100) 1,592 (100) 3,721 (100)

Time for collecting data

2001 1,341 (3.3) - 37 (20.2) - 172 (4.6)

2002-2003 6,221 (15.3) - 109 (59.6) - 814 (21.9)

2004-2005 7,933 (19.5) - 37 (20.2) - 529 (14.2)

2006-2007 7,747 (19.1) 1 (0.7) - - 415 (11.2)

2008-2009 8,062 (19.8) 42 (30.0) - - 618 (16.6)

2010-2011 5,772 (14.2) 46 (32.9) - 211 (13.3) 550 (14.8)

2012-2013 3,575 (8.8) 51 (36.4) - 1,381 (86.8) 623 (16.7)

Participants

Sex

Men 15,655 (38.5) 71 (50.7) 75 (41.0) 638 (40.1) 1,532 (41.2)

Women 24,992 (61.5) 69 (49.3) 108 (59.0) 954 (59.9) 2,186 (58.8)

Age (years)

15-24 years 1,892 (4.7) 7 (5.0) 6 (3.3) 118 (7.4) 335 (9.0)

25-34 years 5,173 (12.7) 25 (17.9) 24 (13.1) 140 (8.8) 523 (14.1)

35-44 years 8,471 (20.8) 28 (20.0) 34 (18.6) 225 (14.1) 772 (20.8)

45-54 years 10,985 (27.0) 19 (13.6) 51 (27.9) 395 (24.8) 860 (23.1)

55+ years 14,031 (34.5) 61 (43.6) 68 (37.2) 714 (44.9) 1,213 (32.6)

Education

Low level 20,764 (51.1) 40 (28.6) 168 (91.8) 521 (32.7) 2,084 (56.0)

High level 18,425 (45.3) 96 (68.6) 12 (6.6) 1,024 (64.3) 1,429 (38.4)

Employment

Unemployed 6,849 (16.9) 32 (22.9) 31 (16.9) 522 (32.8) 826 (22.2)

Not unemployed 32,781 (80.6) 106 (75.7) 146 (79.8) 1,035 (65.0) 2,783 (74.8)

Disadvantaged smokers (based on work situation and education)

Yes 23,644 (58.2) 55 (39.3) 172 (94.0) 825 (51.8) 2,416 (64.9)

No 15,534 (38.2) 82 (58.6) 9 (4.9) 729 (45.8) 1,114 (29.9)

Smoking

<20 pack-years 13,615 (33.5) 48 (34.3) 56 (30.6) 507 (31.9) 1,391 (37.4)

≥20 pack-years 26,368 (64.9) 91 (65.0) 119 (65.0) 1,063 (66.8) 2,274 (61.1)

Fagerström 1–6 points 29,264 (72.0) 102 (72.9) 124 (67.8) 1,139 (71.6) 2,600 (69.9)

Fagerström 7–10 points 11,142 (27.4) 38 (27.1) 56 (30.6) 445 (28.0) 1,093 (29.4)

<20 cigarettes per day 17,230 (42.4) 53 (37.9) 82 (44.8) 725 (45.5) 1,528 (41.1)

≥20 cigarettes per day 22,950 (56.5) 87 (62.1) 96 (52.5) 867 (54.5) 2,155 (57.9)

Heavy smokers (based on pack-years, Fagerström score and daily consumption)

No 9,845 (24.2) 30 (21.4) 46 (25.1) 356 (22.4) 988 (26.6)

Yes 30,591 (75.3) 109 (77.9) 135 (73.8) 1,213 (76.2) 2,711 (72.9)

Compliance with programme (based on attendance)

Not compliant 14,479 (35.6) 44 (31.4) 1 (0.6) 691 (43.4) 1,064 (28.6)

Compliant 25,731 (63.3) 89 (63.6) 182 (99.4) 825 (51.8) 2,470 (66.4)

Living with a smoker

No 25,802 (63.5) 101 (72.1) 120 (65.6) 1,117 (70.2) 2,316 (62.2)

Yes 14,410 (35.5) 38 (27.1) 61 (33.3) 451 (28.3) 1,358 (36.5)

Living with othersb

Living alone 8,754 (21.5) 52 (37.1) - 656 (41.2) 744 (20.0)

Living with children (+/- adults) 7,717 (19.0) 38 (27.1) - 365 (22.9) 744 (20.0)

Living with adults (no children) 8,436 (20.8) 49 (35.0) - 543 (34.1) 692 (18.6)

Housing situationb

Residential property 11,811 (29.1) 63 (45.0) - 556 (34.9) 844 (22.7)

Co-operative dwelling 2,172 (5.3) 6 (4.3) - 139 (8.7) 184 (4.9)

Rented accommodation 10,464 (25.7) 64 (45.7) - 828 (52.0) 1,070 (28.8)

Other housing 248 (0.6) 4 (2.9) - 34 (2.1) 62 (1.7)

Recommendation

Page 7 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



8

No 16,509 (40.6) 35 (25.0) 82 (44.8) 459 (28.8) 1,544 (41.5)

Yes from health care personal 18,927 (46.6) 100 (71.4) 53 (29.0) 1,069 (67.2) 1,770 (47.6)

Yes from others 4,047 (10.0) - 48 (26.2) - 305 (8.2)

Attempts to quit

No previous attempts 12,258 (30.2) 55 (39.3) 38 (20.8) 565 (35.5) 1,121 (30.1)

1-3 previous attempts 20,605 (50.7) 74 (52.9) 85 (46.5) 813 (51.1) 1,835 (49.3)

> 3 previous attempts 5,526 (13.6) 11 (7.9) 38 (20.8) 178 (11.2) 543 (14.6)

Yes unknown no. of attempts 1,397 (3.4) - 20 (10.9) - 137 (3.7)

Smoking cessation clinic

Setting

Publicly oriented c 31,008 (76.3) 91 (65.0) 97 (53.0) 1,592 (100) 1,780 (47.8)

Hospital (incl. midwives) 8,198 (20.2) 17 (12.1) 82 (44.8) 0 1,415 (38.0)

Other 1,445 (3.6) 32 (22.9) 4 (2.2) 0 526 (14.1)

Geographic area

Capital Region 13,353 (32.9) 23 (16.4) 69 (37.7) 368 (23.1) 1,845 (49.6)

Region Zealand 5,856 (14.4) 4 (2.9) 78 (42.6) 131 (8.2) 248 (6.7)

South Denmark 10,378 (25.5) 27 (19.3) 17 (9.3) 318 (20.0) 601 (16.2)

Central Denmark 9,237 (22.7) 80 (57.1) 16 (8.7) 569 (35.7) 868 (23.3)

Region North 1,827 (4.5) 6 (4.3) 3 (1.6) 206 (12.9) 159 (4.3)

Smoking cessation Intervention

Programme format

Individual 5,878 (14.5) 127 (90.7) 28 (15.3) 166 (10.4) 1,707 (45.9)

Group 34,773 (85.5) 13 (9.3) 155 (84.7) 1,426 (89.6) 2,014 (54.1)

Target audience

Patients and relations 3,647 (9.0) 31 (22.1) 20 (10.9) 44 (2.8) 978 (26.3)

Employees (workplace course) 10,060 (24.8) 4 (2.9) 44 (24.0) 76 (4.8) 649 (17.4)

”Ordinary citizens” 22,132 (54.4) 71 (50.7) 107 (58.5) 1,259 (79.1) 1,386 (37.3)

Mixed 2,516 (6.2) 1 (0.7) 6 (3.3) 76 (4.8) 84 (2.3)

Pregnant women (and partners) 1,156 (2.8) 2 (1.4) 4 (2.2) 4 (0.3) 80 (2.2)

Other 1,125 (2.8) 31 (22.1) 2 (1.1) 133 (8.4) 543 (14.6)

Medication offered for free

No free medication 15,324 (37.7) 120 (85.7) 60 (32.8) 1,342 (84.3) 1,641 (44.1)

Free for days (<1 week) 17,367 (42.7) 8 (5.7) 97 (53.0) 39 (2.5) 880 (23.7)

Free for ≥1 week 4,843 (11.9) 12 (8.6) 26 (14.2) 205 (12.9) 976 (26.2)

Counselling free of charge

Yes 36,544 (89.9) 137 (97.9) 183 (100) 1,589 (99.8) 3,318 (89.2)

No 4,066 (10.0) 3 (2.1) 0 0 400 (10.8)

Planned relapse preventionb

No 13,413 (33.0) 58 (41.4) - 945 (59.4) 898 (24.1)

Yes 11,751 (28.9) 82 (58.6) - 647 (40.6) 1,308 (35.2) a Due to missing values not all variables add up to the total number (and 100%).

b Data obtained from 2006 and on going.

C Covers interventions in the municipalities and on pharmacies.

Low education level was defined as no education except school or short work-related

courses11. Unemployment meant without a job, on sick leave, or receiving compensation (in

contrast to everyone else including employees, students/patients under education, or retired,

and parents on maternity/paternity leave)11.

Patients were defined as disadvantaged if unemployed or had a low education11. Heavy

smokers were defined by ≥20 pack-years, smoked ≥20 grams of tobacco/day, or ≥7 points on

the Fagerström score10,17.

Statistical analyses

Results were reported as absolute numbers and percentages, including missing data, loss to

follow-up, and sensitivity analyses according to the RECORD guidelines18 for population and

clinical databases (base-case). To be able to compare to randomised controlled trials, results

were also reported according to the Russell Standards19, where non-respondents were

presumed to have relapsed (worse-case).

Differences in continuous abstinence were tested separately for men and women using

logistic regression analyses. Initial analyses included selected prognostic factors from table 2

Page 8 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



9

adjusted for sex and age. Hereafter, the multivariate model was fitted. The final analyses were

adjusted for the prognostic factors listed in Table 4, and all predictors were entered together.

Patients with missing values were excluded from the analyses. The multivariate analysis was

also performed for all patients together in order to obtain the odds ratio (OR) for women

compared with men. Statistically significant predictors of continuous abstinence were

identified. Results were displayed as OR and corresponding 95% confidence intervals (CI).

Non-respondent analyses were performed using a χ2-test to compare respondents with non-

respondents; compliant with non-compliant; and intentionally not followed up with followed

up patients according to the characteristics listed in table 2.

A two-sided p-value of <0.05 was considered statistically significant. All statistical calculations

were performed using StataIC 14.

Data access and cleaning

In this study we had full access to the entire database population in the Smoking Cessation

Database. All Civil Registration Numbers (CRN; a unique 10-diget number including date of

birth and sex assigned to every Dane at birth or to emigrants) were checked according to

official validation rules. Non-valid CRNs were corrected according to the Civil Registration

System. Age and sex was corrected accordingly.

In data from 2001-2005 data were checked manually before registration. Questionnaires with

missing or non-valid data were returned to the smoking cessation units with instructions on

how to correct data. From 2006 data validation rules were set up in the online registration

application. Dates were validated in order to avoid non-excising dates, and rules were applied

in order to make sure that obligatory data were entered.

Multiple quit attempts

It was possible for patients to enrol repeatedly, and thereby be registered in the database

with two (or more) different entries specifying the intervention, baseline data, and a follow-

up for each intervention.

Due to the collection of the CRN it was possible to identify patients with multiple

interventions from 2006–2013. Before 2006 this was not possible. Patients participating in

multiple interventions have therefore not been excluded from either period.

The extent of duplicates for the 29,102 patients from 2006–2013 was 1,607 corresponding to

6.6% of the entries. We assumed this was similar before 2006 and will take it into account in

the interpretation of the findings.

Results This study initially included 46,287. Subsequently 12,052 (26%) patients were lost to follow-

up, and 34,235 patients were included in the analyses. The level of missing values was

considered small; 0–5% except for free supportive medication at 7.2%. The characteristics are

given in table 2.

Page 9 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



10

Overall 33% (11,184) of the responding patients reported to be continuously abstinent after 6

months. If the non-respondents were considered to be smokers the proportion was 24%. Quit

rates according to type of intervention and sex are shown in table 3.

Table 3: Continuous abstinence after 6 months, according to smoking cessation intervention. Worse-case

counted the non-respondents as smokers.

Base-case (RECORD criteria18

) Worse-case (RUSSEL criteria19

)

All Men Women All Men Women

Smoking cessation intervention n % % % n % % %

Come & Quit 960 22.5 21.7 23.0 1,592 13.6 14.1 13.3

Gold Standard Programme 30,400 32.8 35.0 31.5 40,651 24.5 26.1 23.6

Health Promotion Counselling 71 32.9 47.4 17.1 140 17.1 25.4 8.7

Crash Courses 159 27.7 36.4 21.5 183 24.0 32.0 18.5

Other 2,645 34.8 35.9 34.1 3,721 24.8 25.3 24.4

Only small differences in quit rates were seen between men and women in regard to the more

intensive interventions (Come & Quit, GSP, and other). The short interventions were more

effective among men compared with women.

Predictors of abstinence

In the fully adjusted model women were significantly less likely to stay abstinent compared

with men; 17% (OR=0.83, 95% CI: 0.79-0.88).

The GSP was the only intervention with a significant outcome for both men and women (table

4).

Table 4: Explanatory variables included in the final multivariate logistic regression analyses. In addition

the model was also adjusted for time of data collection and geographic region.

The results were considered significant if the 95% CI did not include the value 1. Statistically significant

results are marked with an *.

Multivariate analysesa

OR (95% CI)

Multivariate analysesa

OR (95% CI)

Men Women

Smoking cessation intervention

Come & Quit 1 1

Gold Standard Programme 1.70 (1.29-2.24) * 1.35 (1.07-1.72) *

Health Promotion Counselling 2.69 (1.27-5.73) * 0.51 (0.19-1.38)

Crash Courses 1.02 (0.56-1.87) 0.55 (0.31-0.96) *

Other 1.53 (1.13-2.08) * 1.30 (0.99-1.69)

Participants

Age (years)

15-24 years 1 1

25-34 years 1.22 (0.92-1.63) 1.32 (1.09-1.60) *

35-44 years 1.38 (1.05-1.81) * 1.31 (1.09-1.57) *

45-54 years 1.50 (1.15-1.97) * 1.33 (1.11-1.60) *

55+ years 1.48 (1.14-1.94) * 1.38 (1.15-1.65) *

Disadvantaged smokersa

No 1 1

Yes 0.81 (0.73-0.89) * 0.82 (0.76-0.89) *

Heavy smokersb

No 1 1

Yes 0.72 (0.65-0.81) * 0.66 (0.61-0.71) *

Compliance with programmec

No 1 1

Yes 3.62 (3.27-4.00) * 3.54 (3.26-3.84) *


No 1 1

Yes 0.94 (0.86-1.02) 0.92 (0.86-0.99) *

Smoking Cessation Clinic

Page 10 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



11

Setting

Citizen aimed 1 1

Hospital (incl. midwives) 1.05 (0.93-1.20) 1.19 (1.07-1.31) *

Other 1.06 (0.87-1.28) 1.05 (0.88-1.24)

Smoking Cessation Intervention

Programme format

Individual 1 1

Group 0.95 (0.84-1.08) 0.95 (0.87-1.05)


No free medication 1 1

Free for days (<1 week) 0.91 (0.82-1.00) 0.90 (0.83-0.98) *

Free for ≥1 week 1.00 (0.86-1.15) 0.91 (0.81-1.03) a Disadvantaged smokers: unemployed and receiving unemployment benefits and/or low education (no education except schooling and/or

only short work-related courses) 11

b Heavy smokers: smoking ≥20 pack-years and/or daily consumption of ≥20 cigarettes and/or Fagerström nicotine dependency score of ≥7

point 10,17

c Compliance with the programme was defined as having attended at least 75% of the scheduled meetings or for Come & Quit at least 4

sessions 15

Though a very low number of patients, health promotion counselling seemed to be the most

effective intervention for men (OR=2.69; 1.27–5.73), followed by GSP (OR=1.70; 1.29–2.24)

and other interventions (OR=1.53; 1.13–2.08). The effect of crash courses was not significant

for men. For women only GSP increased the effect significantly (OR=1.35; 1.07–1.72).

In both men and women compliance to the programme was the most pronounced predictor of

success, but also increasing age, not being a disadvantaged or a heavy smoker were predictors

(see table 4).

Some effect of the time of data collection was present, and the likelihood of staying

continuously abstinent for 6 months was slightly higher during the beginning of the data

collection (data not shown).

Non-respondent analyses

We performed a non-respondent analysis comparing respondents with non-respondents. The

two groups were significantly different in regard to all variables tested. The differences were

in the range of 0.2%–16.8%. Time of collection, age, education, employment, pack-years,

compliance, housing situation, setting, geographic area, and planned relapse prevention

differed with more than 5%.

Comparing patients intentionally not followed up with those who were we found differences

in the range of 0.3%–8.4%. Time of collection, geographic area, and planned relapse

prevention differed with more than 5%.

Discussion Overall every 3rd GSP intervention resulted in a successful outcome after 6 months.

Compared with women men were more successful with an extra 1 in 6 patients being

continuously abstinent. Only GSP showed a significant result regardless of sex even after

adjusting for independent variables affecting the outcome.

Interestingly the short interventions seemed to be highly effective for men, while women

halved their odds of success following a short intervention. For both sexes especially

compliance, but also increasing age, not being a disadvantaged or a heavy smoker were

predictors of successful quitting.

Page 11 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



12

This study has limitations as well as strengths. The non-respondent analyses showed that the

respondents were more compliant, indicating that the respondents were more likely to be

continuously abstinent. Therefore the results based on the RECORD criteria might

overestimate the quit rate if extrapolated to non-respondents. In contrast the compliance of

the patients with and without intended follow-up was more alike. Some of the identified

differences could be due to the large sample-size.

The follow-up rate was relatively high (74%), and the high number of patients from across the

country and across settings was a strength in this study. Even though the coverage was high

the SCDB might not cover all activities. However, only 3 of 98 municipalities never reported to

the database. Because all smokers in Denmark had access to smoking cessation clinics free of

charge and without referral we considered the study to be likely free of selection bias.

The SCI activities in the regions of Denmark differed more than the distribution of smokers20.

Relatively, Region North treated less smokers while Capital Region treated more patients than

expected based on the number of smokers in each region. However, even the most active

region treated on average only 0,6% of the smokers annually which is far less than the

recommended 5%21.

A further strength was the few missing data. We handled missing data according to the

RECORD guidelines18. Also we reported the continuous abstinence as the primary outcome in

contrast to point prevalence that has several limitations22.

The self-reporting was a limitation, since patients are likely to overestimate their success by

3–6%, compared with CO-validated outcomes23–25. We had no reason to assume that the

overestimation was unevenly distributed among the different interventions. Therefore the

groups should be comparable even though the quit rates might be slightly overestimated in

general. Due to different cultural traditions, smoking habits, and socio-economic conditions,

generalisation should be considered carefully.

The implications of using the routinely collected health data from the SCDB in this study must

be considered sparse, since it is in line with the purpose of the database. Only minor changes

in data collection took place over time in order to include new supportive medicine; and the

eligibility has changed over time due to changes in the Danish healthcare system 14. We

consider the completeness and precision of the data to be high. We are not able to identify

possible misclassification but we expect the occurrence to be very low. We are also aware of

other potential confounders such as genetic predisposition, co-morbidities, competing

addictions and lifestyle factors not included in the analysis due to lack of information.

The high effectiveness of the GSP for both men and women in our study was also seen in

randomised and controlled trials evaluating the program against treatment as usual26,27. A

review found intensive group interventions to be the most effective compared with other

formats28.

Compliance was the most important predictor and increased the odds of abstinence more the

3.5 fold regardless of sex. An earlier study showed a dose-response between compliance and

continuous abstinence for GSP; the more sessions attended the greater chance of

succeeding15. It should be mentioned that compliant patients in our study had several

characteristics that were associated with a high quit rate.

Page 12 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



13

In line with others we found that even though women were more likely to attend a smoking

cessation intervention they were significantly less likely to succeed than men28,29. Bohadana

et al. also confirmed these findings, which could be explained by the differences in nicotine

and behavioural dependence in women and men30. Other studies found no difference in

regard to sex31,32, or that women were more likely to quit smoking33.

Though only few patients undertook short programmes, they showed promising results for

men, but significantly worse results for women. Brief interventions are generally

recommended though the overall effect is low. In addition the setting could be of relevance as

a recent review found no effect of short interventions among surgical patients 34.

Interestingly, offering free NRT or other supportive medicine had a negative effect on the

outcome for women. The literature is contradictive in this matter. A recent study from

England showed no effect of free NRT in combination with a supportive quit-line in patients

who wanted to quit35. In contrast another study found that offering free NRT increased the

chances of success significantly36. A possible explanation could be the influence from other

non-individual variables, such as the type of health system, the local general dental practice or

the availability of over-the-counter drugs. Further studies are needed to clarify which group

of smokers under which conditions would benefit from free NRT.

From a society point of view it is highly interesting that the GSP is effective across different

socio-economic groups. Systematic implementation of GSP would therefore induce high

effectiveness in lower socio-economic groups with the highest smoking prevalence. Only by

collecting data nationwide in a clinical database, like the SCDB, is it possible to document this

important effect. Furthermore, free NRT, other supportive medication, and self-payment of

counselling did not show any association with the quit rate, in agreement with a recent

publication on financial incentives for smoking cessation37.

This study has raised a new hypothesis on the effectiveness of short interventions among men

in real-life, which should be further investigated.

Another area requiring further investigation is the effectiveness of smoking cessation among

groups with very high smoking prevalence, such as mentally ill patients. Recent research

indicates that smoking is associated with the development of psychosis, because psychosis

develops earlier and more frequently among smokers that among non-smokers38. The high

prevalence of smoking among psychiatric patients have traditionally been interpreted as a

way of self-medication, but this is now questioned by a meta-analysis showing that smoking

cessation improves the mental condition for both smokers with and without a psychiatric

diagnosis39.

A final perspective of major interest is that smoking cessation databases can be used for early

warning; e.g. to follow the effect of smoking cessation interventions in a country instead of

waiting to see the effect directly on smoking related illness and death. We would recommend

other countries to establish national smoking cessation databases for these purposes and for

comparison of effects between countries.

Conclusion Over time Danish smoking cessation interventions have shown to be effective in real-life.

After all, 1 in 3 smokers stay abstinent at 6 months follow-up or 1 in 4 if non-respondents are

judged smokers. Compliance is the main predictor of successful quitting. We expected to find

Page 13 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



14

that the GSP would be the most effective intervention, but interestingly, short programmes

also seem to have relatively high effect among men, but the absolute numbers are very small.

Only the comprehensive standard programme in Denmark, GSP, works across sex.

Acknowledgements We thank all participants who agreed to register their data. We thank all staff at the

participating smoking cessation units and at the coordination office. We also thank the

Ministry of Health, the Danish Health Authority, and Bispebjerg and Frederiksberg Hospital

for financing the Danish Smoking Cessation Database. Dr. Fernández is partly supported by

Grant RTICC RD12/0036/0053 (Instituto de Salud Carlos III, Subdirección General de

Evaluación y Fomento de la Investigación, co-funded by the European Regional Development

Fund, FEDER). The funders were not involved in the research project.

Competing interest All authors have completed the ICMJE uniform disclosure form at

www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and

declare: no support from any organisation for the submitted work; no financial relationships

with any organisations that might have an interest in the submitted work in the previous

three years; no other relationships or activities that could appear to have influenced the

submitted work.

Data sharing Data from the SCDB are archived in The Danish Data Archive. Project description, anonymised

dataset, and statistical codes used in this study are available from the corresponding author.

All authors, external and internal, had full access to all of the data (including statistical reports

and tables) in the study and can take responsibility for the integrity of the data and the

accuracy of the data analysis.

Contributors MR and HT contributed to the conception, design and acquisition of data. MR and EF

contributed to the analysis of data. MR, EF and HT contributed to the interpretation of data.

MR drafted the manuscript and EF and HT revised it critically for important intellectual

content. All the authors gave final approval of the version to be published. HT is the guarantor.

Copyright The Corresponding Author has the right to grant on behalf of all authors and does grant on

behalf of all authors, an exclusive licence (or non exclusive for government employees) on a

worldwide basis to the BMJ Publishing Group Ltd to permit this article (if accepted) to be

published in BMJ editions and any other BMJPGL products and sublicences such use and

exploit all subsidiary rights, as set out in our licence.

Page 14 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



15

Transparency declaration The lead author (study guarantors) affirms that the manuscript is an honest, accurate, and

transparent account of the study being reported; that no important aspects of the study have

been omitted; and that any discrepancies from the study as planned (and, if relevant,

registered) have been explained.

References 1. WHO report on the global tobacco epidemic, 2015 Raising taxes on tobacco. (Assecced on April 25, 2016, at

http://apps.who.int/iris/bitstream/10665/178574/1/9789240694606_eng.pdf?ua=1)

2. Lim SS, Vos T, Flaxman AD, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors

and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet

2013;380(9859):2224–60.

3. The Health Consequences of Smoking—50 Years of Progress A Report of the Surgeon General. United States Department of

Health and Human Services, 2014. (Assecced on April 25, 2016, at http://www.surgeongeneral.gov/library/reports/50-years-of-progress/full-report.pdf).

4. Eriksen M, Mackay J, Schluger NW, Gomeshtapeh FI, Drope J. The Tobacco Atlas, 5th edition, 2015. (Assecced on May 3,

2016, at http://www.tobaccoatlas.org/)

5. World Health Organisation. Draft comprehensive global monitoring framework and targets for the prevention and control of

noncommunicable diseases (A66/8), 2013. (Assecced on May 3, 2016, at

http://apps.who.int/gb/ebwha/pdf_files/WHA66/A66_8-en.pdf).

6. Thomson G, Edwards R, Wilson N, Blakely T. What are the elements of the tobacco endgame? Tob Control 2012;21(2):293–5.

7. Danish smoking habits [Danskernes rygevaner]. Copenhagen: Danish Health Authority, The Danish Cancer Society, Danish

Heart Foundation, Danish Lung Association, 2013. (Assecced on May 3, 2016, at

http://sundhedsstyrelsen.dk/da/sundhed/tobak/tal-og-undersoegelser/danskernes-rygevaner/2013)

8. Kjaer NT, Evald T, Rasmussen M, Juhl HH, Mosbech H, Olsen KR. The effectiveness of nationally implemented smoking

interventions in Denmark. Prev Med (Baltim) 2007;45(1):12–4.

9. Olsen KR, Bilde L, Juhl HH, et al. Cost-effectiveness of the Danish smoking cessation interventions: subgroup analysis based on

the Danish Smoking Cessation Database. Eur J Heal Econ HEPAC Heal Econ Prev care 2006;7(4):255–64.

10. Neumann T, Rasmussen M, Heitmann BL, Tønnesen H. Gold Standard Program for Heavy Smokers in a Real-Life Setting. Int J

Environ Res Public Health 2013;10(9):4186–99.

11. Neumann T, Rasmussen M, Ghith N, Heitmann BL, Tønnesen H. The Gold Standard Programme: smoking cessation interventions for disadvantaged smokers are effective in a real-life setting. Tob Control 2013;22(e9):Epub 2012 Jun 16.

12. Rasmussen M, Heitmann BL, Tønnesen H. Effectiveness of the Gold Standard Programmes (GSP) for Smoking Cessation in

Pregnant and Non-Pregnant Women. Int J Environ Res Public Health 2013;10(8):3653–66.

13. Kehlet M, Schroeder T, Tønnesen H. The Gold Standard Program for Smoking Cessation is Effective for Participants Over 60

Years of Age. Int J Environ Res Public Health 2015;12(3):2574–87.

14. Rasmussen M, Ammari ABH, Pedersen B, Tønnesen H. Smoking cessation intervention activities and outcome before, during and after the national Healthcare Reform in Denmark. Clin Heal Promot 2012;2(1):26–35.

15. Ghith N, Ammari ABH, Rasmussen M, Frølich A, Cooper K, Tønnesen H. Impact of compliance on quit rates in a smoking

cessation intervention: population study in Denmark. Clin Heal Promot 2012;2(3):111–9.

16. Danish Cancer Association. About Kom & Kvit (Come & Quit). (Assecced on April 25, 2016, at

https://www.cancer.dk/komogkvit/engelsk/)

17. Heatherton TF, Kozlowski LT, Frecker RC, Fagerström KO. The Fagerström Test for Nicotine Dependence: a revision of the Fagerström Tolerance Questionnaire. Br J Addict 1991;86(9):1119–27.

18. Benchimol EI, Smeeth L, Guttmann A, et al. The REporting of studies Conducted using Observational Routinely-collected health

Data (RECORD) Statement. PLOS Med 2015;12(10):e1001885.

19. West R, Hajek P, Stead L, Stapleton J. Outcome criteria in smoking cessation trials: proposal for a common standard. Addiction

2005;100(3):299–303.

20. Van der Meer R, Wagena E. Smoking cessation for chronic obstructive pulmonary disease. Database Syst Rev 2001;(1):1–27.

21. Public health guideline: Stop smoking services (PH10). NICE National Institute for Health and Care Excellence, 2013. (Assecced

on April 25, 2016, at https://www.nice.org.uk/guidance/ph10).

Page 15 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



16

22. Poulsen PB, Dollerup J, Møller AM. Is a percentage a percentage? Systematic review of the effectiveness of Scandinavian

behavioural modification smoking cessation programmes. Clin Respir J 2010;4(1):3–12.

23. Ferguson J, Bauld L, Chesterman J, Judge K. The English smoking treatment services: one-year outcomes. Addiction 2005;100

Suppl:59–69.

24. Judge K, Bauld L, Chesterman J, Ferguson J. The English smoking treatment services: short-term outcomes. Addiction 2005;100

Suppl:46–58.

25. Pisinger C, Vestbo J, Borch-Johnsen K, Thomsen T, Jørgensen T. Acceptance of the smoking cessation intervention in a large

population-based study: the Inter99 study. Scand J Public Health 2005;33(2):138–45.

26. Møller AM, Villebro N, Pedersen T, Tønnesen H. Effect of preoperative smoking intervention on postoperative complications: a randomised clinical trial. Lancet 2002;359(9301):114–7.

27. Borglykke A, Pisinger C, Jørgensen T, Ibsen H. The effectiveness of smoking cessation groups offered to hospitalised patients

with symptoms of exacerbations of chronic obstructive pulmonary disease (COPD). Clin Respir J 2008;2(3):158–65.

28. Bauld L, Bell K, McCullough L, Richardson L, Greaves L. The effectiveness of NHS smoking cessation services: a systematic

review. J Public Health (Oxf) 2010;32(1):71–82.

29. Martínez C, Martínez-Sánchez JM, Ballbè M, et al. Smoking cessation in hospital workers: effectiveness of a coordinated program in 33 hospitals in Catalonia (Spain). Cancer Nurs 2012;35(5):327–36.

30. Bohadana A, Nilsson F, Rasmussen T, Martinet Y. Gender differences in quit rates following smoking cessation with

combination nicotine therapy: influence of baseline smoking behavior. Nicotine Tob Res 2003;5(1):111–6.

31. Puente D, Cabezas C, Rodriguez-Blanco T, et al. The role of gender in a smoking cessation intervention: a cluster randomized

clinical trial. BMC Public Health 2011;11:369.

32. Chatkin JM, Abreu CM, Blanco DC, et al. No gender difference in effectiveness of smoking cessation treatment in a Brazilian real-life setting. Int J Tuberc Lung Dis 2006;10(5):499–503.

33. Fidler J, Ferguson SG, Brown J, Stapleton J, West R. How does rate of smoking cessation vary by age, gender and social grade?

Findings from a population survey in England. Addiction 2013;108:1680–5.

34. Thomsen T, Villebro N, Møller AM. Interventions for preoperative smoking cessation. Cochrane database Syst Rev

2014;3:CD002294.

35. Ferguson J, Docherty G, Bauld L, et al. Effect of offering different levels of support and free nicotine replacement therapy via an English national telephone quitline: randomised controlled trial. BMJ 2012;344:e1696.

36. An LC, Schillo BA, Kavanaugh AM, et al. Increased reach and effectiveness of a statewide tobacco quitline after the addition of

access to free nicotine replacement therapy. Tob Control 2006;15(4):286–93.

37. Halpern SD, French B, Small DS, et al. Randomized trial of four financial-incentive programs for smoking cessation. N Engl J

Med 2015;372(22):2108–17.

38. Gurillo P, Jauhar S, Murray RM, MacCabe JH. Does tobacco use cause psychosis? Systematic review and meta-analysis. The

Lancet Psychiatry 2015;2(8):718–25.

39. Taylor G, McNeill A, Girling A, Farley A, Lindson-Hawley N, Aveyard P. Change in mental health after smoking cessation:

systematic review and meta-analysis. BMJ 2014;348:g1151.

Page 16 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



83x35mm (300 x 300 DPI)

Page 17 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



192x105mm (300 x 300 DPI)

Page 18 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



The RECORD statement – checklist of items, extended from the STROBE statement, that should be reported in observational studies using

routinely collected health data.

Item

No.

STROBE items Location in

manuscript where

items are reported

RECORD items Location in

manuscript

where items are

reported

Title and abstract

1 (a) Indicate the study’s design

with a commonly used term in

the title or the abstract (b)

Provide in the abstract an

informative and balanced

summary of what was done and

what was found

Done – page 2 RECORD 1.1: The type of data used

should be specified in the title or

abstract. When possible, the name of

the databases used should be included.

RECORD 1.2: If applicable, the

geographic region and timeframe within

which the study took place should be

reported in the title or abstract.

RECORD 1.3: If linkage between

databases was conducted for the study,

this should be clearly stated in the title

or abstract.

Done – page 1

Done (abstract) –

page 2

Not relevant – no

linkage

Introduction

Background

rationale

2 Explain the scientific background

and rationale for the investigation

being reported

Done – page 4

Objectives 3 State specific objectives,

including any prespecified

hypotheses

Last paragraph in

introduction – page 4

Methods

Study Design 4 Present key elements of study

design early in the paper

Done – page 4

Setting 5 Describe the setting, locations,

and relevant dates, including

periods of recruitment, exposure,

follow-up, and data collection

See Study design,

Setting, Intervention,

and Data - page 4-5-

6

Participants 6 (a) Cohort study - Give the

eligibility criteria, and the

See Participants, and

Data – page 5-6

RECORD 6.1: The methods of study

population selection (such as codes or

Done – page 5-6

Page 19 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960

on October 26, 2020 by guest. Protected by copyright. http://bmjopen.bmj.com/ BMJ Open: first published as 10.1136/bmjopen-2016-013553 on 27 February 2017. Downloaded from



sources and methods of selection

of participants. Describe methods

of follow-up

Case-control study - Give the


sources and methods of case

ascertainment and control

selection. Give the rationale for

the choice of cases and controls

Cross-sectional study - Give the



of participants

(b) Cohort study - For matched

studies, give matching criteria

and number of exposed and

unexposed

Case-control study - For matched


and the number of controls per

case

Not relevant

algorithms used to identify subjects)

should be listed in detail. If this is not

possible, an explanation should be

provided.

RECORD 6.2: Any validation studies

of the codes or algorithms used to select

the population should be referenced. If

validation was conducted for this study

and not published elsewhere, detailed

methods and results should be provided.

RECORD 6.3: If the study involved

linkage of databases, consider use of a

flow diagram or other graphical display

to demonstrate the data linkage process,

including the number of individuals

with linked data at each stage.

Not relevant

Not relevant

Variables 7 Clearly define all outcomes,

exposures, predictors, potential

confounders, and effect

modifiers. Give diagnostic

criteria, if applicable.

See Outcomes –

page 6-7-8

RECORD 7.1: A complete list of codes

and algorithms used to classify

exposures, outcomes, confounders, and

effect modifiers should be provided. If

these cannot be reported, an explanation

should be provided.

See table 2

(characteristics) –

page 7-8

Data sources/

measurement

8 For each variable of interest, give

sources of data and details of

methods of assessment

(measurement).

Describe comparability of

assessment methods if there is

more than one group

See Outcomes –

page 6-7-8

Bias 9 Describe any efforts to address

potential sources of bias

Bias and limitations

in discussion – page

12

Page 20 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




Study size 10 Explain how the study size was

arrived at

Figure 1: Flowchart

– page 6

Quantitative

variables

11 Explain how quantitative

variables were handled in the

analyses. If applicable, describe

which groupings were chosen,

and why

See Outcomes –

page 6-7-8

Statistical

methods

12 (a) Describe all statistical

methods, including those used to

control for confounding

(b) Describe any methods used to

examine subgroups and

interactions

(c) Explain how missing data

were addressed

(d) Cohort study - If applicable,

explain how loss to follow-up

was addressed

Case-control study - If

applicable, explain how matching

of cases and controls was

addressed

Cross-sectional study - If

applicable, describe analytical

methods taking account of

sampling strategy

(e) Describe any sensitivity

analyses

See Statistical

analyses – page 8-9

Data access and

cleaning methods

.. RECORD 12.1: Authors should

describe the extent to which the

investigators had access to the database

population used to create the study

population.

RECORD 12.2: Authors should provide

information on the data cleaning

methods used in the study.

See Data Access

and Cleaning –

page 9

Linkage .. RECORD 12.3: State whether the study

included person-level, institutional-

Not relevant - no

linkage

Page 21 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




level, or other data linkage across two

or more databases. The methods of

linkage and methods of linkage quality

evaluation should be provided.

Results

Participants 13 (a) Report the numbers of

individuals at each stage of the

study (e.g., numbers potentially

eligible, examined for eligibility,

confirmed eligible, included in

the study, completing follow-up,

and analysed)

(b) Give reasons for non-

participation at each stage.

(c) Consider use of a flow

diagram

Figure 1: Flowchart

– page 6

RECORD 13.1: Describe in detail the

selection of the persons included in the

study (i.e., study population selection)

including filtering based on data

quality, data availability and linkage.

The selection of included persons can

be described in the text and/or by means

of the study flow diagram.

See Figure 1:

Flowchart, and

results (1th

paragraph text on

missing values) –

page 6+9

Descriptive data 14 (a) Give characteristics of study

participants (e.g., demographic,

clinical, social) and information

on exposures and potential

confounders

(b) Indicate the number of

participants with missing data for

each variable of interest

(c) Cohort study - summarise

follow-up time (e.g., average and

total amount)

See table 2, and

results (1th

paragraph text on

missing values) –

page 7-8+9

Outcome data 15 Cohort study - Report numbers of

outcome events or summary

measures over time

Case-control study - Report

numbers in each exposure

category, or summary measures

of exposure

Cross-sectional study - Report

numbers of outcome events or

summary measures

Done – page 10

Main results 16 (a) Give unadjusted estimates See Predictors of

Page 22 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




and, if applicable, confounder-

adjusted estimates and their

precision (e.g., 95% confidence

interval). Make clear which

confounders were adjusted for

and why they were included

(b) Report category boundaries

when continuous variables were

categorized

(c) If relevant, consider

translating estimates of relative

risk into absolute risk for a

meaningful time period

Abstinence

(Included based on

preliminary

analyses) – page 10

See table 2 – page 7-

8

Not relevant

Other analyses 17 Report other analyses done—e.g.,

analyses of subgroups and

interactions, and sensitivity

analyses

Non-respondent

analyses – page 11

Discussion

Key results 18 Summarise key results with

reference to study objectives

Beginning of

discussion – page 11

Limitations 19 Discuss limitations of the study,

taking into account sources of

potential bias or imprecision.

Discuss both direction and

magnitude of any potential bias

Paragraph 3-8 – page

12

RECORD 19.1: Discuss the

implications of using data that were not

created or collected to answer the

specific research question(s). Include

discussion of misclassification bias,

unmeasured confounding, missing data,

and changing eligibility over time, as

they pertain to the study being reported.

Paragraph 8 in

discussion – page

12

Interpretation 20 Give a cautious overall

interpretation of results

considering objectives,

limitations, multiplicity of

analyses, results from similar

studies, and other relevant

evidence

Paragraph 9-13(-17)

– page 12-13

Generalisability 21 Discuss the generalisability

(external validity) of the study

results

Paragraph 13 – page

13

Page 23 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




Other Information

Funding 22 Give the source of funding and

the role of the funders for the

present study and, if applicable,

for the original study on which

the present article is based

Acknowledgements

– page 14

Accessibility of

protocol, raw

data, and

programming

code

.. RECORD 22.1: Authors should provide

information on how to access any

supplemental information such as the

study protocol, raw data, or

programming code.

Data sharing (after

acknow-

ledgements) –

page 14

*Reference: Benchimol EI, Smeeth L, Guttmann A, Harron K, Moher D, Petersen I, Sørensen HT, von Elm E, Langan SM, the RECORD Working

Committee. The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) Statement. PLoS Medicine 2015;

in press.

*Checklist is protected under Creative Commons Attribution (CC BY) license.

Page 24 of 24


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




Effectiveness of the Gold Standard Programme Compared with Other Smoking Cessation Interventions in Denmark: A

Cohort Study

Journal: BMJ Open

Manuscript ID bmjopen-2016-013553.R1


Date Submitted by the Author: 20-Dec-2016




Smoking and tobacco


Keywords: smoking cessation, national database, effectiveness, smoking cessation interventions


BMJ Open on O


http://bmjopen.bm

j.com/

BM



ownloaded from



1

Effectiveness of the Gold Standard Programme Compared with Other Smoking

Cessation Interventions in Denmark: A Cohort Study



Mette Rasmussen

PhD student

Hanne Tønnesen

Director


Esteve Fernández

Director


Esteve Fernández

Associate Professor


Hanne Tønnesen

Professor


Hanne Tønnesen

Professor

Correspondence to Mette Rasmussen e-mail: [email protected]

Page 1 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



2

Abstract

Objectives: We compared the effectiveness of the Gold Standard Programme (a comprehensive

smoking cessation intervention commonly used in Denmark) with other face-to-face smoking

cessation programmes in Denmark after implementation in real life, and we identified factors

associated with successful quitting.

Design: Prospective cohort study.

Setting: A total of 423 smoking cessation clinics from different settings reported data from

2001–2013.

Participants: In total, 82,515 patients were registered. Smokers ≥15 years old and attending a

programme with planned follow-up were included. Smokers who did not want further

contact, who intentionally were not followed up or who lacked information about the

intervention that they received were excluded. A total of 46,287 smokers were included.

Interventions: Various real-life smoking cessation interventions were identified and

compared: The Gold Standard Programme, Come & Quit, crash courses, health promotion

counselling (brief intervention) and other interventions.

Main outcome: Self-reported continuous abstinence for 6 months.

Results: Overall, 33% (11,184) were continuously abstinent after 6 months; this value was

24% when non-respondents were considered smokers. The follow-up rate was 74%.

Women were less likely to remain abstinent, OR: 0.83 (CI: 0.79–0.87). Short interventions

were more effective among men. After adjusting for confounders, the Gold Standard

Programme was the only intervention with significant results across sex, increasing the odds

of abstinence by 70% for men and 35% for women. In particular, compliance, and to a lesser

degree, mild smoking, older age, and not being disadvantaged were associated with positive

outcomes for both sexes. Compliance increased the odds of abstinence more than 3.5-fold.

Conclusions: Over time, Danish smoking cessation interventions have been effective in real life.


to have relatively strong effects among men, but the absolute numbers are very small. Only

the comprehensive Gold Standard Programme works across sexes.

Page 2 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



3


• This study was based on a large cohort of smokers from all regions and settings in

Denmark; 46,287 smokers were included in the study, and the follow-up rate was high

(74%).

• The study was based on routinely collected health data with high completeness and

precision, and the implications were considered minimal, as the research question was

in line with the purposes of the database.

• Confounding effects were carefully considered and adjusted for, but we cannot exclude

the possibility of residual confounding from other potential confounders, such as

genetic predispositions, co-morbidities, competing addictions and lifestyle factors not

considered due to a lack of information.

• A limitation is that the results were based on self-reporting since patients are likely to

overestimate their success; we assumed that overestimations were evenly distributed

and that the groups were thus comparable in spite of potentially slightly overestimated

quit rates.

• Due to varying cultural traditions, smoking habits, and socio-economic conditions,

generalisations should be considered carefully.

Page 3 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



4

Introduction Tobacco is the most damaging and preventable lifestyle factor affecting public health globally

and nationally1,2. Its harmful effects are well documented3. Globally, the WHO (World Health

Organization) estimates that approximately 6 million people die from smoking-related

diseases yearly1. Many countries, including Denmark, have introduced restrictive laws and

strategies to reduce smoking4. More than 12,800 people in Denmark die as a consequence of

smoking annually, corresponding to 1 in 4 deaths4.

Over the last 15–20 years, many initiatives have been launched to help smokers quit. Smoking


measures have been implemented, including smoking bans, higher tobacco taxes, and

restrictions on tobacco sales and advertising. Recently, Denmark signed on to the WHO's goal

to reduce smoking by 30% by 20255, and specific regions are working towards implementing

a tobacco endgame6. Furthermore, there are many other resources to help smokers quit, such

as Quit-lines, national campaigns, training materials, and more recently, aid based on

information technology tools. These efforts have contributed to an overall change in smoking

climates and attitudes. In Denmark, smoking prevalence has declined by 0.5–1% per annum

during the last decade. In 2013, 17% of the Danish population over 15 years of age smoked

daily, and an additional 6% smoked occasionally7.

Since 1995, the Gold Standard Programme (GSP) has become routine in Denmark, and the

vast majority of smoking cessation interventions offered are the GSP8. It is a comprehensive

intervention comprising 5 meetings over 6 weeks and fulfilling Intensive Clinical Intervention

requirements9. Programme counsellors are specially trained to provide this manual-based

patient education programme. Smokers are either referred to the intervention by health

practitioners, or they can contact programme providers themselves. The GSP has proven to be

highly effective and cost-effective, even across subgroups10–15, but its effectiveness has not yet

been compared to that of other programmes. In addition to the GSP, other face-to-face

methods (e.g., crash courses, health promotion counselling, alternative treatments and Come

& Quit programmes) have been used and evaluated through the national Danish Smoking

Cessation Database (SCDB). The aim of this study was to compare the effectiveness of the GSP

with the effectiveness of other face-to-face smoking cessation programmes used in Denmark.


months. We also aimed to identify factors associated with successful smoking cessation.

Methods

Study design

This prospective cohort study on the SCDB included patients treated from 2001–2013 with

follow-up until 2014. The SCDB lists approximately 80–90% of all clinics performing face-to-

face interventions used in Denmark16, and we thus consider this a representative sample. The

Danish Data Protection Agency (2014–41–3370) and Scientific Ethics Committee (H–C–FSP–

2010–049) approved this study and the Danish Data Protection Agency (2000–54–0013) also

approved the SCDB.

Page 4 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



5

Setting

During the study, 423smoking cessation clinics reported data from municipal clinics,


could attend smoking cessation interventions free of charge with or without referrals.


2001–2005, this proportion was 19%, and from 2006–2012, it was 4%, likely due to

structural changes made in the Danish healthcare system16.

Intervention

Different real-life smoking cessation interventions were identified and compared with the

data registered in the SCDB (see table 1).

In accordance with the guidelines, patients who attended at least 75% of the scheduled

meetings were considered compliant17. For Come & Quit18 (see below), 4 meetings

corresponded to 75% of the GSP8.

Table 1: Descriptions of smoking cessation interventions examined in this study.

Intervention

Gold Standard Programme

The GSP is the standard smoking cessation intervention in Denmark. Counsellor training and teaching materials are

developed by the Danish Cancer Society.

Patients and counsellors decide whether to attend individual or group counselling. The first two weeks cover sessions

on ambivalence and motivation, on the pros and cons of smoking versus cessation, and on setting a quit date. After

the quit date, the last 3 sessions cover risk situations, withdrawal symptoms, medical support services, relapse

prevention methods, and ways to manage a smoke-free life12,13

.

Come & Quit

This concept was developed to attract smokers who do not frequently visit smoking cessation clinics. Each patient has

an individual meeting with a counsellor. The concept includes eight 1½-hour meetings on different themes in open

groups. Each patient can choose how the course is structured and which meetings to attend. Between meetings,

patients can receive text messages, e-mails, and/or phone calls according to their individual needs18

. Come & Quit has

been registered in the SCDB since 2011.

Crash courses

Crash courses consist of one meeting of approximately 1½ hour that are often held in large groups (up to 24 smokers).

The meetings contain information on smoking cessation, the use of nicotine replacement treatments, and additional

smoking cessation resources8.

Health promotion counselling (brief intervention)

This intervention method is based on the five stages of readiness to change. The counselling is intended to support the

patient to move forward while taking into account the initial stage of change. It also involves elements of short

interventions that have proven effective in the modification of alcohol habits, e.g., personal feedback8.

Other

This category includes all other interventions, e.g., acupuncture and special treatments concepts. Interventions in

which telephone consultations are substituted for some of the GSP face-to-face meetings are also registered under

this category.

Participants

In 2001–2013, 82,515 smokers were registered in the SCDB after providing informed consent

(see figure 1).

Inclusion criteria: Patients ≥15 years old at the beginning of the programme who attended a


Page 5 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



6


patients who were intentionally not followed up because the smoking cessation clinic decided

beforehand not to; and patients without information on which intervention they received.

In total, 46,287 smokers who were followed up for 6 months were included (figure 1). Of

them, 26,0% were lost to follow up because they did not respond or because their smoking

status was missing. The remaining 34,235 patients were included in the outcome analyses.

Overall, 82,387 patients were included in the non-respondent analyses.

Figure 1: Flowchart. In total, 82,515 smokers were registered in the SCDB and 36,228 were excluded,

leaving 46,287 smokers in the study population. Of them, 26% of the study population were lost to follow-

up, leaving 34,235 smokers included in the outcome analyses.

Data

We used data from the SCDB8. The database was established in 2000 as a research database.

The SCDB is available to all providers of smoking cessation intervention, and it is free of

charge. Data are reported to the SCDB using standardised questionnaires on smoking

histories, socio-demographic characteristics, treatments, and follow-up.

Beginning in 2006, minor adjustments were made to the questionnaires and follow-up

procedures. No validation of self-reported smoking status was required8. Follow-up was 6

months after the scheduled quit date or, secondarily, the date of course completion. From

2001–2005, the information was collected by mail or telephone, and at least one reminder

was required. For 2006 and later, the data were collected by telephone exclusively. After four

attempts to reach the patient, of which at least one was made in the evening, the patient was

reported as a non-respondent.

Outcomes

Primary outcome:


last treatment date) to the 6-month follow-up ±1 month.

Other variables

Factors associated with a positive outcome were studied after controlling for interventions,

the time of collection, age, disadvantaged patients, heavy smoking, compliance, living with a


Most variables were collected in categories. Age and daily tobacco consumption data

(grams/day) and Fagerström scores on nicotine dependency (from 0–10 points)19 were

collected as continuous data. The data were categorised as shown in table 2.

Data on GPS and other interventions were available throughout the study period, but data on

crash courses were only provided before 2006. Finally, Come & Quit data were recorded from

2011.

A low education level was defined as no education except primary school or short work-

related courses13. Unemployment meant without a job, on sick leave, or receiving

Page 6 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



7

compensation (in contrast to everyone else, including employees, students/patients under

education, retirees, and parents on maternity/paternity leave)13.

Patients were defined as disadvantaged if they had been unemployed or had a low level of

education13. Heavy smokers were defined as follows: ≥20 pack-years, smoking ≥20 grams of

tobacco/day, or reaching ≥7 points on the Fagerström score12,19.


Results are reported as absolute numbers and percentages, including missing data, loss to

follow-up, and non-respondent analyses according to the RECORD guidelines20 for population

and clinical databases (base-case). To compare these data to randomised controlled trials, the

results were also reported according to the Russell Standards21, whereby non-respondents

were presumed to have relapsed (worst case).

Odds ratios were estimated using logistic regression analyses for men and women separately

to test for differences in continuous abstinence levels. Initial analyses included selected

prognostic factors from table 2 adjusted for sex and age. Hereafter, the multivariable mixed

effect regression model for clustered data was fitted, and predictors were included based on

the initial analyses and established knowledge. The final analyses were adjusted for the time

of data collection, geographic regions, age, being a disadvantaged smoker, heavy smoking,

compliance, living with a smoker, setting, individual or group format, and supportive

medication offered for free (see Table 4), and all predictors were entered together. Patients

with missing values were excluded from the analyses. A multivariable analysis was also

performed for all patients together to obtain the odds ratio (OR) for women compared to that

for men. Statistically significant predictors of continuous abstinence were identified. The

results are displayed as OR values and as corresponding 95% confidence intervals (CI). Non-

respondent analyses were performed using a χ2-test to compare respondents with non-

respondents; compliant patients with non-compliant patients; and patients who were

intentionally not followed up with followed up patients according to the characteristics listed

in table 2.


were performed using Stata/IC 14 (StataCorp LP).


In this study, we had full access to the entire SCDB population. All CPR-numbers (CPR; a

unique 10-digit number including the date of birth and sex assigned to every Dane at birth or

to immigrants) were checked according to official validation rules. Invalid CPRs were

corrected according to the Civil Registration System22. Age and sex were corrected

accordingly.

Data from 2001–2005 were checked manually prior to registration. Questionnaires with

missing or invalid data were returned to the smoking cessation units with instructions on

how to correct the data. In 2006, data validation rules were established in the online

registration application. Dates were validated to avoid non-excising dates, and rules were

applied to ensure that required data were entered.

Page 7 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



8


It was possible for patients to enrol repeatedly and to thereby be registered in the database



Due to the collection of the CPR, it was possible to identify patients who had multiple

interventions from 2006–2013. Before 2006, this was not possible. Patients participating in

multiple interventions were therefore not excluded from either period.

The extent of duplicates for the 29,102 patients from 2006–2013 was 1,607 for 6.6% of the

entries. We assumed that this value was similar before 2006 and take this it into account in

our interpretation of the findings.

Results This study initially included 46,287 patients. Subsequently 12,052 (26%) patients were lost to

follow-up, and 34,235 patients were included in the analyses. This number of missing values

was considered small, 0–5%, except for free supportive medication, which was 7.2%. The

characteristics are given in table 2.

Table 2: Characteristics of the 46,287 included smokers by intervention type. Dashes indicate that the

variable was not measured.

GSP Health promotion

counselling

Crash courses Come & Quit Other

n (%) n (%) n (%) n (%) n (%)

Totala 40,651 (100) 140 (100) 183 (100) 1,592 (100) 3,721 (100)

Time for data collection

2001 1,341 (3.3) - 37 (20.2) - 172 (4.6)

2002–2003 6,221 (15.3) - 109 (59.6) - 814 (21.9)

2004–2005 7,933 (19.5) - 37 (20.2) - 529 (14.2)

2006–2007 7,747 (19.1) 1 (0.7) - - 415 (11.2)

2008–2009 8,062 (19.8) 42 (30.0) - - 618 (16.6)

2010–2011 5,772 (14.2) 46 (32.9) - 211 (13.3) 550 (14.8)

2012–2013 3,575 (8.8) 51 (36.4) - 1,381 (86.8) 623 (16.7)

Participants

Sex

Men 15,655 (38.5) 71 (50.7) 75 (41.0) 638 (40.1) 1,532 (41.2)

Women 24,992 (61.5) 69 (49.3) 108 (59.0) 954 (59.9) 2,186 (58.8)

Age (years)

15–24 years 1,892 (4.7) 7 (5.0) 6 (3.3) 118 (7.4) 335 (9.0)

25–34 years 5,173 (12.7) 25 (17.9) 24 (13.1) 140 (8.8) 523 (14.1)

35–44 years 8,471 (20.8) 28 (20.0) 34 (18.6) 225 (14.1) 772 (20.8)

45–54 years 10,985 (27.0) 19 (13.6) 51 (27.9) 395 (24.8) 860 (23.1)

55+ years 14,031 (34.5) 61 (43.6) 68 (37.2) 714 (44.9) 1,213 (32.6)

Education

Low level 20,764 (51.1) 40 (28.6) 168 (91.8) 521 (32.7) 2,084 (56.0)

High level 18,425 (45.3) 96 (68.6) 12 (6.6) 1,024 (64.3) 1,429 (38.4)

Employment

Unemployed 6,885 (16.9) 32 (22.9) 31 (16.9) 522 (32.8) 830 (22.3)

Not unemployed 32,750 (80.6) 106 (75.7) 146 (79.8) 1,035 (65.0) 2,779 (74.7)

Disadvantaged smokers (by work situation and education)

Yes 23,654 (58.2) 55 (39.3) 172 (94.0) 825 (51.8) 2,417 (65.0)

No 15,526 (38.2) 82 (58.6) 9 (4.9) 729 (45.8) 1,113 (29.9)

Smoking

<20 pack-years 13,615 (33.5) 48 (34.3) 56 (30.6) 507 (31.9) 1,391 (37.4)

≥20 pack-years 26,368 (64.9) 91 (65.0) 119 (65.0) 1,063 (66.8) 2,274 (61.1)





Heavy smokers (based on pack-years, Fagerström scores and daily consumption levels)

Page 8 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



9

No 9,845 (24.2) 30 (21.4) 46 (25.1) 356 (22.4) 988 (26.6)

Yes 30,591 (75.3) 109 (77.9) 135 (73.8) 1,213 (76.2) 2,711 (72.9)


Not compliant 14,479 (35.6) 44 (31.4) 1 (0.6) 691 (43.4) 1,064 (28.6)

Compliant 25,731 (63.3) 89 (63.6) 182 (99.4) 825 (51.8) 2,470 (66.4)


No 25,802 (63.5) 101 (72.1) 120 (65.6) 1,117 (70.2) 2,316 (62.2)

Yes 14,410 (35.5) 38 (27.1) 61 (33.3) 451 (28.3) 1,358 (36.5)

Living with othersb

Living alone 8,754 (21.5) 52 (37.1) - 656 (41.2) 744 (20.0)



Housing situationb




Other housing 248 (0.6) 4 (2.9) - 34 (2.1) 62 (1.7)

Referral

No 16,509 (40.6) 35 (25.0) 82 (44.8) 459 (28.8) 1,544 (41.5)

Yes, from health care personal 18,927 (46.6) 100 (71.4) 53 (29.0) 1,069 (67.2) 1,770 (47.6)

Yes, from others 4,047 (10.0) - 48 (26.2) - 305 (8.2)

Attempts to quit






Setting



Other 1,445 (3.6) 32 (22.9) 4 (2.2) 0 526 (14.1)

Geographic area

Capital Region 13,353 (32.9) 23 (16.4) 69 (37.7) 368 (23.1) 1,845 (49.6)

Region Zealand 5,856 (14.4) 4 (2.9) 78 (42.6) 131 (8.2) 248 (6.7)

South Denmark 10,378 (25.5) 27 (19.3) 17 (9.3) 318 (20.0) 601 (16.2)

Central Denmark 9,237 (22.7) 80 (57.1) 16 (8.7) 569 (35.7) 868 (23.3)

North Denmark Region 1,827 (4.5) 6 (4.3) 3 (1.6) 206 (12.9) 159 (4.3)


Programme format

Individual 5,878 (14.5) 127 (90.7) 28 (15.3) 166 (10.4) 1,707 (45.9)

Group 34,773 (85.5) 13 (9.3) 155 (84.7) 1,426 (89.6) 2,014 (54.1)

Target audience




Mixed 2,516 (6.2) 1 (0.7) 6 (3.3) 76 (4.8) 84 (2.3)


Other 1,125 (2.8) 31 (22.1) 2 (1.1) 133 (8.4) 543 (14.6)




Free for ≥1 week 4,843 (11.9) 12 (8.6) 26 (14.2) 205 (12.9) 976 (26.2)


Yes 36,544 (89.9) 137 (97.9) 183 (100) 1,589 (99.8) 3,318 (89.2)

No 4,066 (10.0) 3 (2.1) 0 0 400 (10.8)


No 13,413 (33.0) 58 (41.4) - 945 (59.4) 898 (24.1)

Yes 11,751 (28.9) 82 (58.6) - 647 (40.6) 1,308 (35.2) a Due to missing values, not all variables add up to the total number (and 100%).

b Data obtained from 2006 and to the present.

C Covers interventions in the municipalities and pharmacies.

Overall, 33% (11,184) of the responding patients reported being continuously abstinent after

6 months. If the non-respondents were considered to be smokers, this proportion was 24%.

Crude quit rates by intervention type and sex are shown in table 3.

Page 9 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



10

Table 3: Continuous abstinence after 6 months by smoking cessation intervention not adjusted for

participant characteristics. The worst case counted the non-respondents as smokers.

Base case (RECORD criteria20

) Worst case (RUSSEL criteria21

)



Come & Quit 960 22.5 21.7 23.0 1,592 13.6 14.1 13.3


Health promotion counselling 71 32.9 47.4 17.1 140 17.1 25.4 8.7

Crash courses 159 27.7 36.4 21.5 183 24.0 32.0 18.5

Other 2,645 34.8 35.9 34.1 3,721 24.8 25.3 24.4


In the fully adjusted model, women were significantly less likely to remain abstinent than men

(17% (OR=0.83, 95% CI: 0.79-0.87)).

The GSP was the only intervention to present significant outcomes for both men and women

(table 4).

Table 4: Explanatory variables included in the final multivariable logistic regression analyses. In addition,

the model was also adjusted for the time of data collection and for geographic regions. Statistically

significant results are marked with an *.

Multivariable analysesa

OR (95% CI)

Multivariable analysesa

OR (95% CI)

Men

n=11,724

p

Women

n=18,184

p


Come & Quit 1 1

Gold Standard Programme 1.69 (1.27-2.24) <0.001* 1.31 (1.03-1.68) 0.030*

Health promotion counselling 2.64 (1.21-5.72) 0.014* 0.48 (0.17-1.34) 0.162

Crash courses 1.08 (0.58-2.02) 0.809 0.49 (0.28-0.87) 0.015*

Other 1.50 (1.09-2.06) 0.012* 1.20 (0.91-1.58) 0.194

Participants

Age (years)

15-24 years 1 1

25-34 years 1.22 (0.91-1.62) 0.183 1.29 (1.06-1.57) 0.009*

35-44 years 1.37 (1.04-1.80) 0.027* 1.28 (1.06-1.55) 0.010*

45-54 years 1.49 (1.14-1.96) 0.004* 1.31 (1.08-1.57) 0.005*

55+ years 1.48 (1.13-1.94) 0.005* 1.35 (1.12-1.63) 0.001*


No 1 1

Yes 0.81 (0.73-0.89) <0.001* 0.82 (0.76-0.89) <0.001*

Heavy smokersb

No 1 1

Yes 0.73 (0.65-0.81) <0.001* 0.65 (0.60-0.70) <0.001*


No 1 1

Yes 3.65 (3.29-4.04) <0.001* 3.58 (3.30-3.89) <0.001*


No 1 1

Yes 0.94 (0.86-1.02) 0.142 0.92 (0.86-0.99) 0.025*


Setting

Citizen aimed 1 1

Hospital (incl. midwives) 1.02 (0.85-1.21) 0.851 1.09 (0.94-1.27) 0.250

Other 1.13 (0.89-1.45) 0.319 1.05 (0.84-1.31) 0.682


Programme format

Individual 1 1

Group 0.96 (0.84-1.10) 0.560 0.97 (0.87-1.08) 0.550



Free for days (<1 week) 0.87 (0.78-0.97) 0.014* 0.87 (0.80-0.96) 0.005*

Free for ≥1 week 0.97 (0.82-1.14) 0.695 0.95 (0.83-1.10) 0.503

Page 10 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



11

Hierarchical cluster


Random intercept 0.06 (0.04-0.11) 0.07 (0.04-0.11) a Disadvantaged smokers: unemployed and receiving unemployment benefits and/or low education (no education except primary schooling and/or only short

work-related courses)13

b Heavy smokers: smoking ≥20 pack-years and/or daily consumption of ≥20 cigarettes and/or Fagerström nicotine dependency score of ≥7 points

12,19

c Compliance with the programme was defined as having attended at least 75% of the scheduled meetings

17 or for Come & Quit at least 4 sessions

8

Though applying to very few patients, health promotion counselling seemed to be the most

effective intervention for men (OR=2.64; 1.21–5.71), followed by the GSP (OR=1.69; 1.27–

2.24) and other interventions (OR=1.50; 1.09–2.06). The effect of crash courses was not

significant for men. For women, only the GSP increased the effect significantly (OR=1.31;

1.03–1.68).

For both men and women, programme compliance was the most pronounced predictor of

success, and more advanced age and not being disadvantaged or a heavy smoker were other

predictors (see table 4).

An effect of the time of data collection was present, and the likelihood of remaining

continuously abstinent for 6 months was slightly higher at the start of the data collection

period (data not shown).


We performed a non-respondent analysis of the 46,287 smokers included in the study by

comparing respondents (34,235 smokers) with non-respondents (12,052 smokers lost to

follow-up). Respondents and non-respondents were significantly different in regard to every

variable tested. The largest difference between the two groups (16.8 percentage points) was

seen in regards to compliance, where the smokers lost to follow-up were less likely to be

compliant with the programme. In addition, time of data collection, age, education,

employment, pack-years, housing situation, setting, geographic area, and planned relapse

prevention differed by more than 5 percentage points.

Another analysis performed on 82,387 smokers comparing patients not wanting to be

contacted or who were intentionally not followed up (36,100 smokers) with those who were

(46,287 smokers) showed differences of up to 8.4 percentage points. The largest difference

was geographic area, but time of collection, and planned relapse prevention also differed by

more than 5 percentage points between the compared groups.

Discussion Overall, every 3rd GSP intervention resulted in a successful outcome after 6 months.

Compared with women, men were more successful, with an additional 1 in 6 patients being

continuously abstinent. Only the GSP showed a significant result regardless of sex even after

adjusting for independent variables affecting the outcomes.

Interestingly, the short interventions seemed to be highly effective for men, while women

halved their odds of success following short interventions. For both sexes, compliance, as well

as advanced age and not being a disadvantaged or a heavy smoker were predictors of

successful quitting.

The high effectiveness of the GSP for both men and women in our study was also observed in

randomised and controlled trials evaluating the programme against typical treatments23,24. A

Page 11 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



12


formats25.

Compliance was the most important predictor, increasing the odds of abstinence more than

3.5-fold regardless of sex. An earlier study showed a dose-dependent response between

compliance and continuous abstinence for GSP; the more sessions attended, the greater the

chance of succeeding17. It should be noted that compliant patients included in our study had

several characteristics that were associated with high quit rates.

In line with other studies, we found that even though women were more likely to attend a

smoking cessation intervention, they were significantly less likely to succeed than men25,26.

Bohadana et al. also confirmed these findings, which could be explained by differences in

nicotine and behavioural dependence between women and men27. Other studies have found

no differences in regards to sex28,29 or that women are more likely to quit smoking30.

Though only a few patients undertook short programmes, men showed more promising

results, while women showed significantly worse results. Brief interventions are generally

recommended, though their overall effect is low. In addition, the setting could be of relevance,

as a recent review found no effect of short interventions among surgical patients31.

Interestingly, offering free NRT or other supportive medicine had a negative effect on

outcomes. The literature is contradictory on this matter. A recent study from England showed

no effect of free NRT in combination with a supportive quit-line for patients who wanted to

quit32. In contrast, another study found that offering free NRT increased the chances of

success significantly33. A possible explanation could be the influence of other non-individual

variables, such as the type of health system, local general dental practices or the availability of

over-the-counter drugs. Further studies are needed to clarify which group of smokers under

which conditions would benefit from free NRT.

During the study period from 2001–2013, smoking prevalence in Denmark dropped from

30% to 17% daily smokers, corresponding to 1,230–780 thousand people. Over this period,

82,431 smokers aged 15 years or older received a face-to-face smoking cessation intervention

programme registered in the SCDB, corresponding to approximately 7–11% of all daily

smokers. Converted to a yearly basis, fewer than 1% of the smokers in Denmark have

received a face-to-face smoking cessation intervention. This number is very low compared to

that of England, where 5–10% of the smokers are treated by the Stop Smoking Service29, as

well as compared to national and international guidelines recommending that 5% of all

smokers should receive a smoking cessation intervention yearly. It is difficult to compare the

present data to other countries since, to the best of our knowledge, no other countries have

clinical registers with national coverage.



continuously abstinent. Therefore, the results based on the RECORD criteria may

overestimate the quit rate when extrapolated to non-respondents. In contrast, the compliance

of patients with and without intended follow-up was more similar. Some of the differences

identified could be attributed to the large sample size. The follow-up rate was relatively high

(74%), and the large number of patients from across the country and across settings was a

strength of this study. Even though the coverage was high, the SCDB may not cover all

activities. However, only 3 of the 98 municipalities never reported to the database. SCI

Page 12 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



13

activities across regions of Denmark differed more than the distribution of smokers34.

Relatively, the North Denmark Region treated fewer smokers, while the Capital Region treated

more patients than expected based on the number of smokers in each region. However, even

the most active region has treated only 0.6% of all smokers annually which is far lower than

the recommended 5%35. An additional strength was the low amount of missing data. We

addressed missing data according to RECORD guidelines20. Some of the programmes were

only recorded in the database in a limited part of the study period. Two of the programmes

only had a very low number of participants (0.3 and 0.4%) and the influence on the overall

result is therefore very limited. The programme Come & Quit was established in 2011 but

includes 3.4% of the smokers and may potentially affect the comparative analyses. However,

time for data collection only showed a minor reduction of successful quitting overtime. Thus,

the effect of the crash courses recorded only in the beginning of the period may be slightly

overestimated. We also reported continuous abstinence as the primary outcome, in contrast

to point prevalence, which has several limitations36. The self-reporting was a limitation, as

patients are likely to overestimate their success by 3–6% compared with CO-validated

outcomes37–39. We had no reason to assume that this overestimation was unevenly distributed

among the different interventions. Therefore, the groups should be comparable, even though

the quit rates may be slightly overestimated in general. Due to different cultural traditions,

smoking habits, and socio-economic conditions, generalisations should be considered

carefully. The implications of using the routinely collected health data from the SCDB in this

study must be considered minimal, as the study is in line with the purposes of the database.

Only minor changes in data collection took place over time to include new supportive

medicine, and the eligibility has changed over time due to changes in the Danish healthcare

system16. We consider the completeness and precision of the data to be high8. We are not able

to identify possible misclassifications, but we expect their occurrence to be very low. We are

also aware of other potential confounders such as genetic predisposition, co-morbidities,

competing addictions and lifestyle factors that are not included in the analysis due to a lack of

information.

From a societal perspective, it is highly interesting that the GSP is effective across different

socio-economic groups. A systematic implementation of the GSP would therefore be highly

effective among lower socio-economic groups with the highest smoking prevalence. Only by

collecting nationwide data in a clinical database such as the SCDB is it possible to document

this important effect. Furthermore, free NRTs, other supportive medications, and self-

payment counselling did not show any association with the quit rate, in agreement with a

recent publication on financial incentives for smoking cessation40.


that should be investigated further.



indicates that smoking is associated with the development of psychosis because psychosis

develops earlier and more frequently among smokers than among non-smokers41. The high

prevalence of smoking among psychiatric patients has traditionally been interpreted as a

form of self-medication, but this has now been questioned by a meta-analysis showing that

smoking cessation improves the mental conditions of smokers with and without a psychiatric

diagnosis42.

Page 13 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



14

A final area of major interest is that smoking cessation databases can be used for early

detection, i.e., to follow the effects of smoking cessation interventions across a country rather

than waiting to see the effect directly on smoking related illness and death. We recommend

that other countries establish national smoking cessation databases for these purposes and

for comparing effects between countries.

Conclusion Over time, Danish smoking cessation interventions have been shown to be effective in real

life. Ultimately, 1 in 3 smokers are still abstinent at 6 months of follow-up (or 1 in 4 if non-

respondents are judged as smokers). Compliance is the main predictor of successful quitting.

We expected to find that the GSP would be the most effective intervention, but interestingly,

short programmes also seem to have relatively strong effect among men, though the absolute

numbers are very small. Only the comprehensive standard programme in Denmark, the GSP,

works across sexes.








Competing interests All authors have completed the ICMJE uniform disclosure form at

www.icmje.org/coi_disclosure.pdf (available upon request from the corresponding author)

and declare no support from any organisation for the submitted work, no financial

relationships with any organisations that may have an interest in the submitted work over the

previous three years, and no other relationships or activities that could appear to have

influenced the submitted work.

Data sharing Data from the SCDB are archived in The Danish Data Archive. Project descriptions,

anonymised datasets, and statistical codes used in this study are available from the

corresponding author.

All authors, external and internal, had full access to all of the study data (including statistical

reports and tables) and take responsibility for the integrity of the data and for the accuracy of

the data analysis.



Page 14 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



15

MR drafted the manuscript, and EF and HT revised it critically for important intellectual

content. All of the authors gave final approval of the version to be published. HT is the

guarantor.

Copyright The Corresponding Author assumes the right to grant on behalf of all authors, and does grant

on behalf of all authors, an exclusive licence (or non-exclusive for government employees) on

a global basis for the BMJ Publishing Group Ltd. to allow this article (if accepted) to be

published in BMJ editions and in any other BMJPGL products and sublicenses and such uses

and to exploit all subsidiary rights, as set out in our licence.

Transparency declaration The lead author (study guarantor) affirms that the manuscript is an honest, accurate, and

transparent account of the study being reported, that no important aspects of the study have

been omitted, and that any discrepancies from the study as planned (and, if relevant,






2013;380(9859):2224–60.

3. The Health Consequences of Smoking—50 Years of Progress A Report of the Surgeon General. United States Department of Health and Human Services, 2014. (Assecced on April 25, 2016, at http://www.surgeongeneral.gov/library/reports/50-years-of-

progress/full-report.pdf).










8. Rasmussen M, Tønnesen H. The Danish Smoking Cessation Database. Clin Health Promot 2016;Accepted

9. Clinical Practice Guideline Treating Tobacco Use and Dependence 2008 Update Panel, Liaisons and S. A Clinical Practice

Guideline for Treating Tobacco Use and Dependence: 2008 Update. Am J Prev Med 2008;35(2):158–76.







13. Neumann T, Rasmussen M, Ghith N, Heitmann BL, Tønnesen H. The Gold Standard Programme: smoking cessation

interventions for disadvantaged smokers are effective in a real-life setting. Tob Control 2013;22(e9):Epub 2012 Jun 16.

14. Rasmussen M, Heitmann BL, Tønnesen H. Effectiveness of the Gold Standard Programmes (GSP) for Smoking Cessation in Pregnant and Non-Pregnant Women. Int J Environ Res Public Health 2013;10(8):3653–66.

Page 15 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



16

15. Kehlet M, Schroeder T, Tønnesen H. The Gold Standard Program for Smoking Cessation is Effective for Participants Over 60

Years of Age. Int J Environ Res Public Health 2015;12(3):2574–87.

16. Rasmussen M, Ammari ABH, Pedersen B, Tønnesen H. Smoking cessation intervention activities and outcome before, during

and after the national Healthcare Reform in Denmark. Clin Health Promot 2012;2(1):26–35.


cessation intervention: population study in Denmark. Clin Health Promot 2012;2(3):111–9.

18. Danish Cancer Association. About Kom & Kvit (Come & Quit). (Assecced on April 25, 2016, at

https://www.cancer.dk/komogkvit/engelsk/)

19. Heatherton TF, Kozlowski LT, Frecker RC, Fagerström KO. The Fagerström Test for Nicotine Dependence: a revision of the Fagerström Tolerance Questionnaire. Br J Addict 1991;86(9):1119–27.




2005;100(3):299–303.

22. Pedersen CB. The Danish Civil Registration System. Scand J Public Health 2011;39(7 suppl):22–5.

23. Møller AM, Villebro N, Pedersen T, Tønnesen H. Effect of preoperative smoking intervention on postoperative complications: a

randomised clinical trial. Lancet 2002;359(9301):114–7.





26. Martínez C, Martínez-Sánchez JM, Ballbè M, et al. Smoking cessation in hospital workers: effectiveness of a coordinated

program in 33 hospitals in Catalonia (Spain). Cancer Nurs 2012;35(5):327–36.



28. Puente D, Cabezas C, Rodriguez-Blanco T, et al. The role of gender in a smoking cessation intervention: a cluster randomized

clinical trial. BMC Public Health 2011;11:369.

29. Dobbie F, Hiscock R, Leonardi-Bee J, Murray S, Shahab L, Aveyard P. Evaluating Long-term Outcomes of NHS Stop Smoking

Services (ELONS): a prospective cohort study. Heal Technol Assess 2015;19(95).



31. Thomsen T, Villebro N, Møller AM. Interventions for preoperative smoking cessation. Cochrane database Syst Rev 2014;3:CD002294.

32. Ferguson J, Docherty G, Bauld L, et al. Effect of offering different levels of support and free nicotine replacement therapy via an

English national telephone quitline: randomised controlled trial. BMJ 2012;344:e1696.









Suppl:59–69.


Suppl:46–58.



40. Halpern SD, French B, Small DS, et al. Randomized trial of four financial-incentive programs for smoking cessation. N Engl J

Med 2015;372(22):2108–17.



Page 16 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



17



Page 17 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Table 1: Descriptions of smoking cessation interventions examined in this study.

168x81mm (300 x 300 DPI)

Page 18 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Figure 1: Flowchart. In total, 82,515 smokers were registered in the SCDB and 36,228 were excluded, leaving 46,287 smokers in the study population. Of them, 26% of the study population were lost to follow-

up, leaving 34,235 smokers included in the outcome analyses. Figure 1

Page 19 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Appendix

Non-respondentanalyses:Losttofollow-up.

Theanalysesarerunasatwo-waytablewithmeasuresofassociation(chi2).

Participants

. tab2 r_method FollowUp06, chi2 column missing

Pearson chi2(6) = 1.4e+03 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 9.45 19.88 12.16 2012-2013 3,234 2,396 5,630 13.02 17.60 14.21 2010-2011 4,458 2,121 6,579 19.03 18.32 18.84 2008-2009 6,514 2,208 8,722 17.67 17.54 17.64 2006-2007 6,049 2,114 8,163 19.79 14.31 18.36 2004-2005 6,774 1,725 8,499 17.25 10.27 15.43 2002-2003 5,906 1,238 7,144 3.80 2.07 3.35 2001 1,300 250 1,550 collection Follow-up No follow Total data 6-month follow-up Time of

Pearson chi2(4) = 239.6633 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 7.73 8.93 8.04 Other 2,645 1,076 3,721 2.80 5.24 3.44 Come and Quit 960 632 1,592 0.46 0.20 0.40 Speed courses 159 24 183 0.21 0.57 0.30 Brief Intervention 71 69 140 88.80 85.06 87.82 GSP 30,400 10,251 40,651 intervention Follow-up No follow Total Method/Type of 6-month follow-up

Pearson chi2(2) = 7.5703 Pr = 0.023

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.01 0.04 0.02 . 2 5 7 61.20 61.04 61.16 Female 20,953 7,356 28,309 38.79 38.92 38.83 Male 13,280 4,691 17,971 Sex Follow-up No follow Total 6-month follow-up

Pearson chi2(5) = 553.5021 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.20 0.40 0.25 . 69 48 117 36.30 30.38 34.75 55+ years 12,426 3,661 16,087 27.24 24.78 26.59 45-54 years 9,324 2,986 12,310 20.46 20.94 20.59 35-44 years 7,006 2,524 9,530 11.89 15.07 12.71 25-34 years 4,069 1,816 5,885 3.92 8.44 5.09 15-24 years 1,341 1,017 2,358 course Follow-up No follow Total of the 6-month follow-up beginning Age at the

Page 20 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Pearson chi2(2) = 96.9182 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 3.53 4.27 3.72 . 1,209 515 1,724 44.20 48.58 45.34 High education 15,131 5,855 20,986 52.27 47.15 50.94 Low education 17,895 5,682 23,577 Education Follow-up No follow Total 6-month follow-up

Pearson chi2(2) = 174.9989 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 2.30 3.18 2.53 . 788 383 1,171 16.69 21.45 17.93 Unemployed 5,715 2,585 8,300 81.00 75.37 79.54 Not unemployed 27,732 9,084 36,816 Job situation Follow-up No follow Total 6-month follow-up

100.00 100.00 100.00 Total 34,235 12,052 46,287 3.53 4.13 3.68 . 1,207 498 1,705 59.33 56.52 58.60 Disadvantaged 20,311 6,812 27,123 37.15 39.35 37.72 Not disadvantaged 12,717 4,742 17,459 disadvantaged Follow-up No follow Total Being 6-month follow-up

Pearson chi2(2) = 157.2072 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.67 1.52 1.63 . 572 183 755 66.22 60.10 64.63 ≥20 pack-years 22,672 7,243 29,915 32.10 38.38 33.74 <20 pack-years 10,991 4,626 15,617 years Follow-up No follow Total No. of pack 6-month follow-up

Pearson chi2(2) = 47.6348 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.55 0.80 0.61 . 187 97 284 26.86 29.70 27.60 7-10 points 9,195 3,579 12,774 72.60 69.50 71.79 0-6 points 24,853 8,376 33,229 score Follow-up No follow Total Fagerström 6-month follow-up

Pearson chi2(2) = 14.1003 Pr = 0.001

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.16 0.98 1.11 . 396 118 514 56.02 57.89 56.51 ≥20 cigarettes per da 19,178 6,977 26,155 42.82 41.13 42.38 <20 cigarettes per da 14,661 4,957 19,618 Cigarettes per day Follow-up No follow Total 6-month follow-up

. tab2 b_compliance FollowUp06, chi2 column missing

Pearson chi2(2) = 27.8962 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.49 0.78 0.57 . 168 94 262 75.60 73.65 75.09 Heavy smoker 25,883 8,876 34,759 23.91 25.57 24.34 Not heavy smoker 8,184 3,082 11,266 Heavy smoker Follow-up No follow Total 6-month follow-up

Pearson chi2(2) = 1.1e+03 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.27 2.30 1.54 . 434 277 711 67.68 50.85 63.29 Yes 23,169 6,128 29,297 31.06 46.86 35.17 No 10,632 5,647 16,279 programme Follow-up No follow Total with the 6-month follow-up Compliant

Page 21 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Smokingcessationclinic

Pearson chi2(2) = 11.8403 Pr = 0.003

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.05 1.29 1.11 . 358 155 513 35.63 34.19 35.25 Yes 12,197 4,121 16,318 63.33 64.52 63.64 No 21,680 7,776 29,456 smoker Follow-up No follow Total with a 6-month follow-up Living

Pearson chi2(3) = 14.5823 Pr = 0.002

100.00 100.00 100.00 Total 20,263 8,839 29,102 1.09 1.04 1.07 . 220 92 312 33.82 32.44 33.40 Living with adults (n 6,853 2,867 9,720 30.73 29.85 30.46 Living with children 6,226 2,638 8,864 34.37 36.68 35.07 Living alone 6,964 3,242 10,206 Living with others Follow-up No follow Total 6-month follow-up

Pearson chi2(4) = 392.5174 Pr = 0.000

100.00 100.00 100.00 Total 20,263 8,839 29,102 1.75 2.25 1.90 . 354 199 553 0.91 1.86 1.20 Other 184 164 348 39.74 49.49 42.70 Rental 8,052 4,374 12,426 8.34 9.19 8.59 Partly owned 1,689 812 2,501 49.27 37.22 45.61 Owner 9,984 3,290 13,274 situation Follow-up No follow Total Housing 6-month follow-up

Pearson chi2(3) = 248.9327 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 2.61 3.69 2.89 . 894 445 1,339 10.66 6.22 9.51 Yes, by others (not H 3,650 750 4,400 46.36 50.19 47.35 Yes, by health care p 15,870 6,049 21,919 40.37 39.89 40.25 No 13,821 4,808 18,629 by Follow-up No follow Total Reccommended to quit 6-month follow-up

Pearson chi2(4) = 130.0030 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.94 2.69 2.13 . 664 324 988 3.65 2.51 3.36 Yes unknown attempts 1,251 303 1,554 13.96 12.58 13.60 > 3 attempts 4,780 1,516 6,296 51.19 48.85 50.58 1-3 attempts 17,525 5,887 23,412 29.25 33.37 30.33 None 10,015 4,022 14,037 attempts Follow-up No follow Total Earlier quit 6-month follow-up

. tab2 scc_setting FollowUp06, chi2 column missing

Pearson chi2(4) = 118.9975 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 24.73 23.85 24.50 South Denmark 8,466 2,875 11,341 14.19 12.10 13.65 Region Zealand 4,859 1,458 6,317 4.76 4.73 4.76 North Denmark 1,631 570 2,201 23.83 21.68 23.27 Central Denmark 8,157 2,613 10,770 32.49 37.64 33.83 Capital Region 11,122 4,536 15,658 intervention Follow-up No follow Total Place of the 6-month follow-up

Page 22 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Smokingcessationintervention

.

Pearson chi2(2) = 146.2297 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 4.60 3.59 4.34 Other 1,574 433 2,007 22.17 17.61 20.98 Hospital/Midwife 7,590 2,122 9,712 73.23 78.80 74.68 Citizen aimed 25,071 9,497 34,568 Setting Follow-up No follow Total 6-month follow-up

Pearson chi2(1) = 36.7751 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 83.55 81.13 82.92 Groups 28,603 9,778 38,381 16.45 18.87 17.08 Individually 5,632 2,274 7,906 intervention Follow-up No follow TotalFormat of the 6-month follow-up

Pearson chi2(6) = 216.0385 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.02 0.07 0.03 . 7 9 16 3.25 6.00 3.96 Other 1,111 723 1,834 2.91 2.08 2.69 Pregnant 995 251 1,246 5.98 5.27 5.80 Mixed 2,048 635 2,683 53.82 54.18 53.91 Ordinary citizens 18,425 6,530 24,955 23.66 22.67 23.40 Working place 8,101 2,732 10,833 10.36 9.72 10.20 Patients 3,548 1,172 4,720 Target audience Follow-up No follow Total 6-month follow-up

Pearson chi2(3) = 83.0809 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 7.27 7.11 7.23 . 2,490 857 3,347 12.93 13.57 13.10 Free for one week or 4,426 1,636 6,062 40.89 36.43 39.73 Free for days 14,000 4,391 18,391 38.90 42.88 39.94 No 13,319 5,168 18,487 supportive medication Follow-up No follow Total Free NRT or other 6-month follow-up

Pearson chi2(2) = 81.8218 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.08 0.17 0.10 . 26 21 47 10.35 7.67 9.65 Yes user payment 3,545 924 4,469 89.57 92.16 90.24 No user payment 30,664 11,107 41,771 User payment Follow-up No follow Total 6-month follow-up

.

Pearson chi2(1) = 80.1838 Pr = 0.000

100.00 100.00 100.00 Total 20,263 8,839 29,102 49.11 43.41 47.38 Yes 9,951 3,837 13,788 50.89 56.59 52.62 No 10,312 5,002 15,314 prevention Follow-up No follow Total relapse 6-month follow-up Planned

Page 23 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Non-respondentanalyses:smokersnotwantingtobecontactedorwhowereintentionallynot

followedupversusthosewhowere.


Participant

Pearson chi2(6) = 994.6432 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 12.08 11.86 11.99 2012-2013 5,630 4,246 9,876 14.12 12.58 13.45 2010-2011 6,579 4,503 11,082 18.72 14.55 16.91 2008-2009 8,722 5,207 13,929 17.52 19.37 18.33 2006-2007 8,163 6,935 15,098 18.63 26.39 22.00 2004-2005 8,682 9,445 18,127 15.54 12.39 14.17 2002-2003 7,239 4,436 11,675 3.38 2.86 3.16 2001 1,576 1,024 2,600 collection Followed Not follo Total data 6-month follow-up Time of

Pearson chi2(4) = 228.3708 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 8.04 11.00 9.32 Other 3,744 3,938 7,682 3.42 3.10 3.28 Come and Quit 1,592 1,108 2,700 0.40 0.58 0.48 Speed courses 188 206 394 0.30 0.28 0.29 Brief Intervention 140 100 240 87.84 85.05 86.63 GSP 40,927 30,444 71,371 intervention Followed Not follo Total Method/Type of 6-month follow-up

. tab2 b_age_cat FollowUp06, chi2 column missing

Pearson chi2(2) = 1.5447 Pr = 0.462

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.02 0.02 0.02 . 9 6 15 61.14 60.72 60.96 Female 28,484 21,736 50,220 38.84 39.26 39.03 Male 18,098 14,054 32,152 Sex Followed Not follo Total 6-month follow-up

. tab2 b_education FollowUp06, chi2 column missing

Pearson chi2(5) = 58.0022 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.27 0.49 0.37 . 126 177 303 34.66 33.60 34.20 55+ years 16,147 12,026 28,173 26.58 26.97 26.75 45-54 years 12,386 9,653 22,039 20.60 20.71 20.65 35-44 years 9,600 7,414 17,014 12.76 12.37 12.59 25-34 years 5,945 4,429 10,374 5.12 5.86 5.44 15-24 years 2,387 2,097 4,484 course Followed Not follo Total of the 6-month follow-up beginning Age at the

Pearson chi2(2) = 96.1876 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 3.72 4.41 4.02 . 1,734 1,577 3,311 45.14 41.92 43.74 High education 21,029 15,006 36,035 51.14 53.67 52.24 Low education 23,828 19,213 43,041 Education Followed Not follo Total 6-month follow-up

. tab2 b_disadvantaged FollowUp06, chi2 column missing

Pearson chi2(2) = 11.5754 Pr = 0.003

100.00 100.00 100.00 Total 46,591 35,796 82,387 2.53 2.89 2.68 . 1,179 1,033 2,212 17.87 17.45 17.69 Unemployed 8,328 6,247 14,575 79.59 79.66 79.62 Not unemployed 37,084 28,516 65,600 Job situation Followed Not follo Total 6-month follow-up

Page 24 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



. tab2 b_packyears FollowUp06, chi2 column missing

Pearson chi2(2) = 56.4533 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 3.68 4.20 3.91 . 1,715 1,503 3,218 58.77 60.61 59.57 Disadvantaged 27,380 21,697 49,077 37.55 35.19 36.53 Not disadvantaged 17,496 12,596 30,092 disadvantaged Followed Not follo Total Being 6-month follow-up

. tab2 b_nicotin_dependency FollowUp06, chi2 column missing

Pearson chi2(2) = 35.0457 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.65 2.21 1.89 . 769 792 1,561 64.52 64.42 64.48 ≥20 pack-years 30,061 23,059 53,120 33.83 33.37 33.63 <20 pack-years 15,761 11,945 27,706 years Followed Not follo Total No. of pack 6-month follow-up

. tab2 b_tobacco_consumption FollowUp06, chi2 column missing

Pearson chi2(2) = 29.4824 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.62 0.95 0.76 . 289 340 629 27.56 27.68 27.61 7-10 points 12,840 9,909 22,749 71.82 71.37 71.62 0-6 points 33,462 25,547 59,009 score Followed Not follo Total Fagerström 6-month follow-up

Pearson chi2(2) = 12.9606 Pr = 0.002

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.13 1.39 1.24 . 526 497 1,023 56.44 56.76 56.58 ≥20 cigarettes per da 26,297 20,319 46,616 42.43 41.85 42.18 <20 cigarettes per da 19,768 14,980 34,748 Cigarettes per day Followed Not follo Total 6-month follow-up


Pearson chi2(2) = 30.0704 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.57 0.89 0.71 . 267 320 587 75.01 75.00 75.00 Heavy smoker 34,947 26,847 61,794 24.42 24.11 24.28 Not heavy smoker 11,377 8,629 20,006 Heavy smoker Followed Not follo Total 6-month follow-up

Pearson chi2(2) = 593.0973 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.53 4.19 2.68 . 711 1,501 2,212 63.32 63.72 63.49 Yes 29,502 22,809 52,311 35.15 32.09 33.82 No 16,378 11,486 27,864 programme Followed Not follo Total with the 6-month follow-up Compliant

. tab2 b_living_with_others FollowUp06 if old_new==2, chi2 column missing

Pearson chi2(2) = 55.4289 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.12 1.63 1.34 . 521 585 1,106 35.29 36.39 35.76 Yes 16,440 13,025 29,465 63.60 61.98 62.89 No 29,630 22,186 51,816 smoker Followed Not follo Total with a 6-month follow-up Living

Pearson chi2(3) = 47.7068 Pr = 0.000

100.00 100.00 100.00 Total 29,102 20,794 49,896 1.07 1.63 1.30 . 312 339 651 33.40 33.76 33.55 Living with adults (n 9,720 7,020 16,740 30.46 31.52 30.90 Living with children 8,864 6,554 15,418 35.07 33.09 34.25 Living alone 10,206 6,881 17,087 Living with others Followed Not follo Total 6-month follow-up

Page 25 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from





Pearson chi2(4) = 128.7344 Pr = 0.000

100.00 100.00 100.00 Total 29,102 20,794 49,896 1.90 2.67 2.22 . 553 556 1,109 1.20 1.22 1.20 Other 348 253 601 42.70 39.91 41.53 Rental 12,426 8,298 20,724 8.59 6.98 7.92 Partly owned 2,501 1,452 3,953 45.61 49.22 47.12 Owner 13,274 10,235 23,509 situation Followed Not follo Total Housing 6-month follow-up

Pearson chi2(3) = 21.2984 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 2.87 2.87 2.87 . 1,339 1,029 2,368 9.60 10.53 10.00 Yes, by others (not H 4,472 3,770 8,242 47.15 46.23 46.75 Yes, by health care p 21,967 16,548 38,515 40.38 40.36 40.37 No 18,813 14,449 33,262 by Followed Not follo Total Reccommended to quit 6-month follow-up

Pearson chi2(4) = 59.8356 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 2.16 2.55 2.33 . 1,005 913 1,918 3.41 4.29 3.79 Yes unknown attempts 1,587 1,536 3,123 13.62 13.36 13.51 > 3 attempts 6,346 4,781 11,127 50.52 50.18 50.37 1-3 attempts 23,539 17,963 41,502 30.29 29.62 30.00 None 14,114 10,603 24,717 attempts Followed Not follo Total Earlier quit 6-month follow-up

Pearson chi2(4) = 1.4e+03 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 24.47 23.20 23.92 South Denmark 11,399 8,305 19,704 13.68 22.07 17.33 Region Zealand 6,375 7,900 14,275 4.76 6.44 5.49 North Denmark 2,220 2,306 4,526 23.33 22.86 23.12 Central Denmark 10,868 8,183 19,051 33.76 25.43 30.14 Capital Region 15,729 9,102 24,831 intervention Followed Not follo Total Place of the 6-month follow-up

.

Pearson chi2(2) = 102.0653 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 4.35 5.84 5.00 Other 2,026 2,090 4,116 21.00 21.44 21.19 Hospital/Midwife 9,784 7,675 17,459 74.65 72.72 73.81 Citizen aimed 34,781 26,031 60,812 Setting Followed Not follo Total 6-month follow-up

Pearson chi2(1) = 121.6374 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 82.97 79.97 81.66 Groups 38,655 28,625 67,280 17.03 20.03 18.34 Individually 7,936 7,171 15,107 intervention Followed Not follo TotalFormat of the 6-month follow-up

Page 26 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Pearson chi2(6) = 119.5273 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.03 0.04 0.04 . 16 14 30 3.97 4.75 4.31 Other 1,848 1,702 3,550 2.69 3.08 2.86 Pregnant 1,255 1,103 2,358 5.79 6.80 6.23 Mixed 2,697 2,434 5,131 53.81 52.36 53.18 Ordinary citizens 25,069 18,742 43,811 23.53 21.90 22.82 Working place 10,963 7,841 18,804 10.18 11.06 10.56 Patients 4,743 3,960 8,703 Target audience Followed Not follo Total 6-month follow-up

Page 27 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from





Item

No.


manuscript where

items are reported


manuscript

where items are

reported

Title and abstract







what was found












or abstract.

Done – page 1

Done (abstract) –

page 2

Not relevant – no

linkage

Introduction

Background

rationale



being reported

Done – page 4



hypotheses

Last paragraph in


Methods



Done – page 4





See Study design,



6




Data – page 5-6



Done – page 5-6

Page 28 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960






of follow-up










of participants




unexposed




case

Not relevant




provided.













Not relevant

Not relevant






See Outcomes –

page 6-7-8






should be provided.

See table 2


page 7-8

Data sources/

measurement




(measurement).



more than one group

See Outcomes –

page 6-7-8





12

Page 29 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960





arrived at

Figure 1: Flowchart

– page 6

Quantitative

variables





and why

See Outcomes –

page 6-7-8

Statistical

methods






interactions


were addressed



was addressed




addressed




sampling strategy


analyses

See Statistical


Data access and

cleaning methods





population.




See Data Access

and Cleaning –

page 9



Not relevant - no

linkage

Page 30 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960








Results







and analysed)




diagram

Figure 1: Flowchart

– page 6









See Figure 1:

Flowchart, and

results (1th

paragraph text on

missing values) –

page 6+9





confounders






total amount)

See table 2, and

results (1th

paragraph text on

missing values) –

page 7-8+9



measures over time




of exposure



summary measures

Done – page 10


Page 31 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960












categorized





Abstinence

(Included based on

preliminary



8

Not relevant




analyses

Non-respondent


Discussion



Beginning of








12









Paragraph 8 in

discussion – page

12







evidence

Paragraph 9-13(-17)

– page 12-13



results


13

Page 32 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




Other Information






Acknowledgements

– page 14

Accessibility of

protocol, raw

data, and

programming

code





programming code.

Data sharing (after

acknow-

ledgements) –

page 14



in press.


Page 33 of 33


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




Effectiveness of the Gold Standard Programme Compared with Other Smoking Cessation Interventions in Denmark: A

Cohort Study

Journal: BMJ Open

Manuscript ID bmjopen-2016-013553.R2


Date Submitted by the Author: 03-Feb-2017




Smoking and tobacco


Keywords: smoking cessation, national database, effectiveness, smoking cessation interventions, Denmark


BMJ Open on O


http://bmjopen.bm

j.com/

BM



ownloaded from



1

Effectiveness of the Gold Standard Programme Compared with Other Smoking

Cessation Interventions in Denmark: A Cohort Study



Mette Rasmussen

PhD student

Hanne Tønnesen

Director


Esteve Fernández

Director


Esteve Fernández

Associate Professor


Hanne Tønnesen

Professor


Hanne Tønnesen

Professor

Correspondence to Mette Rasmussen e-mail: [email protected]

Page 1 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



2

Abstract

Objectives: We compared the effectiveness of the Gold Standard Programme (a comprehensive

smoking cessation intervention commonly used in Denmark) with other face-to-face smoking

cessation programmes in Denmark after implementation in real life, and we identified factors

associated with successful quitting.

Design: Prospective cohort study.

Setting: A total of 423 smoking cessation clinics from different settings reported data from

2001–2013.

Participants: In total, 82,515 patients were registered. Smokers ≥15 years old and attending a

programme with planned follow-up were included. Smokers who did not want further

contact, who intentionally were not followed up or who lacked information about the

intervention they received were excluded. A total of 46,287 smokers were included.

Interventions: Various real life smoking cessation interventions were identified and compared:

The Gold Standard Programme, Come & Quit, crash courses, health promotion counselling

(brief intervention) and other interventions.

Main outcome: Self-reported continuous abstinence for 6 months.

Results: Overall, 33% (11,184) were continuously abstinent after 6 months; this value was

24% when non-respondents were considered smokers. The follow-up rate was 74%.

Women were less likely to remain abstinent, OR: 0.83 (CI: 0.79–0.87). Short interventions

were more effective among men. After adjusting for confounders, the Gold Standard

Programme was the only intervention with significant results across sex, increasing the odds

of abstinence by 70% for men and 35% for women. In particular, compliance, and to a lesser

degree, mild smoking, older age, and not being disadvantaged were associated with positive

outcomes for both sexes. Compliance increased the odds of abstinence more than 3.5-fold.

Conclusions: Over time, Danish smoking cessation interventions have been effective in real life.


to have relatively strong effects among men, but the absolute numbers are very small. Only

the comprehensive Gold Standard Programme works across sexes.

Page 2 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



3


• This study was based on a large cohort of smokers from all regions and settings in

Denmark; 46,287 smokers were included in the study, and the follow-up rate was high

(74%).

• The study was based on routinely collected health data with high completeness and

precision, and the implications were considered minimal, as the research question was

in line with the purposes of the database.

• Confounding effects were carefully considered and adjusted for, but we cannot exclude

the possibility of residual confounding from other potential confounders, such as

genetic predispositions, co-morbidities, competing addictions and lifestyle factors not

considered due to a lack of information.

• A limitation is that the results were based on self-reporting since patients are likely to

overestimate their success; we assumed that overestimations were evenly distributed

and that the groups were thus comparable in spite of potentially slightly overestimated

quit rates.

• Due to varying cultural traditions, smoking habits, and socio-economic conditions,

generalisations should be considered carefully.

Page 3 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



4

Introduction Tobacco is the most damaging and preventable lifestyle factor affecting public health globally

and nationally1,2. Its harmful effects are well documented3. Globally, the WHO (World Health

Organization) estimates that approximately 6 million people die from smoking-related

diseases yearly1. Many countries, including Denmark, have introduced restrictive laws and

strategies to reduce smoking4. More than 12,800 people in Denmark die as a consequence of

smoking annually, corresponding to 1 in 4 deaths4.

Over the last 15–20 years, many initiatives have been launched to help smokers quit. Smoking


measures have been implemented, including smoking bans, higher tobacco taxes, and

restrictions on tobacco sales and advertising. Recently, Denmark signed on to the WHO's goal

to reduce smoking by 30% by 20255, and specific regions are working towards implementing

a tobacco endgame6. Furthermore, there are many other resources to help smokers quit, such

as Quit-lines, national campaigns, training materials, and more recently, aid based on

information technology tools. These efforts have contributed to an overall change in smoking

climates and attitudes. In Denmark, smoking prevalence has declined by 0.5–1% per annum

during the last decade. In 2013, 17% of the Danish population over 15 years of age smoked

daily, and an additional 6% smoked occasionally7.

Since 1995, the Gold Standard Programme (GSP) has become routine in Denmark, and the

vast majority of smoking cessation interventions offered are the GSP8. It is a comprehensive

intervention comprising 5 meetings over 6 weeks and fulfilling Intensive Clinical Intervention

requirements9. Programme counsellors are specially trained to provide this manual-based

patient education programme. Smokers are either referred to the intervention by health

practitioners, or they can contact programme providers themselves. The GSP has proven to be

highly effective and cost-effective, even across subgroups10–15, but its effectiveness has not yet

been compared to that of other programmes. In addition to the GSP, other face-to-face

methods (e.g., crash courses, health promotion counselling, alternative treatments and Come

& Quit programmes) have been used and evaluated through the national Danish Smoking

Cessation Database (SCDB). The aim of this study was to compare the effectiveness of the GSP

with the effectiveness of other face-to-face smoking cessation programmes used in Denmark.


months. We also aimed to identify factors associated with successful smoking cessation.

Methods

Study design

This prospective cohort study on the SCDB included patients treated from 2001–2013 with

follow-up until 2014. The SCDB lists approximately 80–90% of all clinics performing face-to-

face interventions used in Denmark16, and we thus consider this a representative sample. The

Danish Data Protection Agency (2014–41–3370) and Scientific Ethics Committee (H–C–FSP–

2010–049) approved this study and the Danish Data Protection Agency (2000–54–0013) also

approved the SCDB.

Page 4 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



5

Setting

During the study, 423smoking cessation clinics reported data from municipal clinics,


could attend smoking cessation interventions free of charge with or without referrals.


2001–2005, this proportion was 19%, and from 2006–2012, it was 4%, likely due to

structural changes made in the Danish healthcare system16.

Intervention

Different real life smoking cessation interventions were identified and compared with the

data registered in the SCDB (see fig 1).

In accordance with the guidelines, patients who attended at least 75% of the scheduled

meetings were considered compliant17. For Come & Quit18 (see below), 4 meetings

corresponded to 75% of the GSP8.

Figure 1: Descriptions of smoking cessation interventions examined in this study.

Participants

In 2001–2013, 82,515 smokers were registered in the SCDB after providing informed consent

(see figure 2).

Inclusion criteria: Patients ≥15 years old at the beginning of the programme who attended a



patients who were intentionally not followed up because the smoking cessation clinic decided

beforehand not to; and patients without information on which intervention they received.

In total, 46,287 smokers who were followed up for 6 months were included (figure 2). Of

them, 26,0% were lost to follow up because they did not respond or because their smoking

status was missing. The remaining 34,235 patients were included in the outcome analyses.

Overall, 82,387 patients were included in the non-respondent analyses.

Figure 2: Flowchart. In total, 82,515 smokers were registered in the SCDB and 36,228 were excluded,

leaving 46,287 smokers in the study population. Of them, 26% of the study population were lost to follow-

up, leaving 34,235 smokers included in the outcome analyses.

Data

We used data from the SCDB8. The database was established in 2000 as a research database.

The SCDB is available to all providers of smoking cessation intervention, and it is free of

charge. Data are reported to the SCDB using standardised questionnaires on smoking

histories, socio-demographic characteristics, treatments, and follow-up.

Page 5 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



6

Beginning in 2006, minor adjustments were made to the questionnaires and follow-up

procedures. No validation of self-reported smoking status was required8. Follow-up was 6

months after the scheduled quit date or, secondarily, the date of course completion. From

2001–2005, the information was collected by mail or telephone, and at least one reminder

was required. For 2006 and later, the data were collected by telephone exclusively. After four

attempts to reach the patient, of which at least one was made in the evening, the patient was

reported as a non-respondent.

Outcomes

Primary outcome:


last treatment date) to the 6-month follow-up ±1 month.

Other variables

Factors associated with a positive outcome were studied after controlling for interventions,

the time of collection, age, disadvantaged patients, heavy smoking, compliance, living with a


Most variables were collected in categories. Age and daily tobacco consumption data

(grams/day) and Fagerström scores on nicotine dependency (from 0–10 points)19 were

collected as continuous data. The data were categorised as shown in table 1.

Data on GPS and other interventions were available throughout the study period, but data on

crash courses were only provided before 2006. Finally, Come & Quit data were recorded from

2011.

A low education level was defined as no education except primary school or short work-

related courses13. Unemployment meant without a job, on sick leave, or receiving

compensation (in contrast to everyone else, including employees, students/patients under

education, retirees, and parents on maternity/paternity leave)13.

Patients were defined as disadvantaged if they had been unemployed or had a low level of

education13. Heavy smokers were defined as follows: ≥20 pack-years, smoking ≥20 grams of

tobacco/day, or reaching ≥7 points on the Fagerström score12,19.


Results are reported as absolute numbers and percentages, including missing data, loss to

follow-up, and non-respondent analyses according to the RECORD guidelines20 for population

and clinical databases (base-case). To compare these data to randomised controlled trials, the

results were also reported according to the Russell Standards21, whereby non-respondents

were presumed to have relapsed (worst case).

Odds ratios were estimated using logistic regression analyses for men and women separately

to test for differences in continuous abstinence levels. Initial analyses included selected

prognostic factors from table 1 adjusted for sex and age. Hereafter, the multivariable mixed

effect regression model for clustered data was fitted, and predictors were included based on

the initial analyses and established knowledge. The final analyses were adjusted for the time

of data collection, geographic regions, age, being a disadvantaged smoker, heavy smoking,

Page 6 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



7

compliance, living with a smoker, setting, individual or group format, and supportive

medication offered for free (see Table 3), and all predictors were entered together. Patients

with missing values were excluded from the analyses. A multivariable analysis was also

performed for all patients together to obtain the odds ratio (OR) for women compared to that

for men. Statistically significant predictors of continuous abstinence were identified. The

results are displayed as OR values and as corresponding 95% confidence intervals (CI). Non-

respondent analyses were performed using a χ2-test to compare respondents with non-

respondents; compliant patients with non-compliant patients; and patients who were

intentionally not followed up with followed up patients according to the characteristics listed

in table 1.


were performed using Stata/IC 14 (StataCorp LP).


In this study, we had full access to the entire SCDB population. All CPR-numbers (CPR; a

unique 10-digit number including the date of birth and sex assigned to every Dane at birth or

to immigrants) were checked according to official validation rules. Invalid CPRs were

corrected according to the Civil Registration System22. Age and sex were corrected

accordingly.

Data from 2001–2005 were checked manually prior to registration. Questionnaires with

missing or invalid data were returned to the smoking cessation units with instructions on

how to correct the data. In 2006, data validation rules were established in the online

registration application. Dates were validated to avoid non-excising dates, and rules were

applied to ensure that required data were entered.


It was possible for patients to enrol repeatedly and to thereby be registered in the database



Due to the collection of the CPR, it was possible to identify patients who had multiple

interventions from 2006–2013. Before 2006, this was not possible. Patients participating in

multiple interventions were therefore not excluded from either period.

The extent of duplicates for the 29,102 patients from 2006–2013 was 1,607 for 6.6% of the

entries. We assumed that this value was similar before 2006 and take this it into account in

our interpretation of the findings.

Results This study initially included 46,287 patients. Subsequently 12,052 (26%) patients were lost to

follow-up, and 34,235 patients were included in the analyses. This number of missing values

was considered small, 0–5%, except for free supportive medication, which was 7.2%. The

characteristics are given in table 1.

Page 7 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



8

Table 1: Characteristics of the 46,287 included smokers by intervention type. Dashes indicate that the

variable was not measured.

GSP Health promotion

counselling

Crash courses Come & Quit Other

n (%) n (%) n (%) n (%) n (%)

Totala 40,651 (100) 140 (100) 183 (100) 1,592 (100) 3,721 (100)

Time for data collection

2001 1,341 (3.3) - 37 (20.2) - 172 (4.6)

2002–2003 6,221 (15.3) - 109 (59.6) - 814 (21.9)

2004–2005 7,933 (19.5) - 37 (20.2) - 529 (14.2)

2006–2007 7,747 (19.1) 1 (0.7) - - 415 (11.2)

2008–2009 8,062 (19.8) 42 (30.0) - - 618 (16.6)

2010–2011 5,772 (14.2) 46 (32.9) - 211 (13.3) 550 (14.8)

2012–2013 3,575 (8.8) 51 (36.4) - 1,381 (86.8) 623 (16.7)

Participants

Sex

Men 15,655 (38.5) 71 (50.7) 75 (41.0) 638 (40.1) 1,532 (41.2)

Women 24,992 (61.5) 69 (49.3) 108 (59.0) 954 (59.9) 2,186 (58.8)

Age (years)

15–24 years 1,892 (4.7) 7 (5.0) 6 (3.3) 118 (7.4) 335 (9.0)

25–34 years 5,173 (12.7) 25 (17.9) 24 (13.1) 140 (8.8) 523 (14.1)

35–44 years 8,471 (20.8) 28 (20.0) 34 (18.6) 225 (14.1) 772 (20.8)

45–54 years 10,985 (27.0) 19 (13.6) 51 (27.9) 395 (24.8) 860 (23.1)

55+ years 14,031 (34.5) 61 (43.6) 68 (37.2) 714 (44.9) 1,213 (32.6)

Education

Low level 20,764 (51.1) 40 (28.6) 168 (91.8) 521 (32.7) 2,084 (56.0)

High level 18,425 (45.3) 96 (68.6) 12 (6.6) 1,024 (64.3) 1,429 (38.4)

Employment

Unemployed 6,885 (16.9) 32 (22.9) 31 (16.9) 522 (32.8) 830 (22.3)

Not unemployed 32,750 (80.6) 106 (75.7) 146 (79.8) 1,035 (65.0) 2,779 (74.7)

Disadvantaged smokers (by work situation and education)

Yes 23,654 (58.2) 55 (39.3) 172 (94.0) 825 (51.8) 2,417 (65.0)

No 15,526 (38.2) 82 (58.6) 9 (4.9) 729 (45.8) 1,113 (29.9)

Smoking

<20 pack-years 13,615 (33.5) 48 (34.3) 56 (30.6) 507 (31.9) 1,391 (37.4)

≥20 pack-years 26,368 (64.9) 91 (65.0) 119 (65.0) 1,063 (66.8) 2,274 (61.1)





Heavy smokers (based on pack-years, Fagerström scores and daily consumption levels)

No 9,845 (24.2) 30 (21.4) 46 (25.1) 356 (22.4) 988 (26.6)

Yes 30,591 (75.3) 109 (77.9) 135 (73.8) 1,213 (76.2) 2,711 (72.9)


Not compliant 14,479 (35.6) 44 (31.4) 1 (0.6) 691 (43.4) 1,064 (28.6)

Compliant 25,731 (63.3) 89 (63.6) 182 (99.4) 825 (51.8) 2,470 (66.4)


No 25,802 (63.5) 101 (72.1) 120 (65.6) 1,117 (70.2) 2,316 (62.2)

Yes 14,410 (35.5) 38 (27.1) 61 (33.3) 451 (28.3) 1,358 (36.5)

Living with othersb

Living alone 8,754 (21.5) 52 (37.1) - 656 (41.2) 744 (20.0)



Housing situationb




Other housing 248 (0.6) 4 (2.9) - 34 (2.1) 62 (1.7)

Referral

No 16,509 (40.6) 35 (25.0) 82 (44.8) 459 (28.8) 1,544 (41.5)

Yes, from health care personal 18,927 (46.6) 100 (71.4) 53 (29.0) 1,069 (67.2) 1,770 (47.6)

Yes, from others 4,047 (10.0) - 48 (26.2) - 305 (8.2)

Attempts to quit






Setting

Page 8 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



9



Other 1,445 (3.6) 32 (22.9) 4 (2.2) 0 526 (14.1)

Geographic area

Capital Region 13,353 (32.9) 23 (16.4) 69 (37.7) 368 (23.1) 1,845 (49.6)

Region Zealand 5,856 (14.4) 4 (2.9) 78 (42.6) 131 (8.2) 248 (6.7)

South Denmark 10,378 (25.5) 27 (19.3) 17 (9.3) 318 (20.0) 601 (16.2)

Central Denmark 9,237 (22.7) 80 (57.1) 16 (8.7) 569 (35.7) 868 (23.3)

North Denmark Region 1,827 (4.5) 6 (4.3) 3 (1.6) 206 (12.9) 159 (4.3)


Programme format

Individual 5,878 (14.5) 127 (90.7) 28 (15.3) 166 (10.4) 1,707 (45.9)

Group 34,773 (85.5) 13 (9.3) 155 (84.7) 1,426 (89.6) 2,014 (54.1)

Target audience




Mixed 2,516 (6.2) 1 (0.7) 6 (3.3) 76 (4.8) 84 (2.3)


Other 1,125 (2.8) 31 (22.1) 2 (1.1) 133 (8.4) 543 (14.6)




Free for ≥1 week 4,843 (11.9) 12 (8.6) 26 (14.2) 205 (12.9) 976 (26.2)


Yes 36,544 (89.9) 137 (97.9) 183 (100) 1,589 (99.8) 3,318 (89.2)

No 4,066 (10.0) 3 (2.1) 0 0 400 (10.8)


No 13,413 (33.0) 58 (41.4) - 945 (59.4) 898 (24.1)

Yes 11,751 (28.9) 82 (58.6) - 647 (40.6) 1,308 (35.2) a Due to missing values, not all variables add up to the total number (and 100%).

b Data obtained from 2006 and to the present.

C Covers interventions in the municipalities and pharmacies.

Overall, 33% (11,184) of the responding patients reported being continuously abstinent after

6 months. If the non-respondents were considered to be smokers, this proportion was 24%.

Crude quit rates by intervention type and sex are shown in table 2.

Table 2: Continuous abstinence after 6 months by smoking cessation intervention not adjusted for

participant characteristics. The worst case counted the non-respondents as smokers.

Base case (RECORD criteria20

) Worst case (RUSSEL criteria21

)



Come & Quit 960 22.5 21.7 23.0 1,592 13.6 14.1 13.3


Health promotion counselling 71 32.9 47.4 17.1 140 17.1 25.4 8.7

Crash courses 159 27.7 36.4 21.5 183 24.0 32.0 18.5

Other 2,645 34.8 35.9 34.1 3,721 24.8 25.3 24.4


In the fully adjusted model, women were significantly less likely to remain abstinent than men

(17% (OR=0.83, 95% CI: 0.79-0.87)).

The GSP was the only intervention to present significant outcomes for both men and women

(table 3).

Table 3: Explanatory variables included in the final multivariable logistic regression analyses. In addition,

the model was also adjusted for the time of data collection and for geographic regions. Statistically

significant results are marked with an *.

Multivariable analysesa Multivariable analyses

a Interaction

Page 9 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



10

OR (95% CI) OR (95% CI) with sex

Men

n=11,724

Women

n=18,184

p


Come & Quit 1 1

Gold Standard Programme 1.69 (1.27-2.24) 1.31 (1.03-1.68) 0.079

Health promotion counselling 2.64 (1.21-5.72) 0.48 (0.17-1.34) 0.013*

Crash courses 1.08 (0.58-2.02) 0.49 (0.28-0.87) 0.054

Other 1.50 (1.09-2.06) 1.20 (0.91-1.58) 0.244

Participants

Age (years)

15-24 years 1 1

25-34 years 1.22 (0.91-1.62) 1.29 (1.06-1.57) 0.918

35-44 years 1.37 (1.04-1.80) 1.28 (1.06-1.55) 0.413

45-54 years 1.49 (1.14-1.96) 1.31 (1.08-1.57) 0.193

55+ years 1.48 (1.13-1.94) 1.35 (1.12-1.63) 0.337


No 1 1

Yes 0.81 (0.73-0.89) 0.82 (0.76-0.89) 0.594

Heavy smokersb

No 1 1

Yes 0.73 (0.65-0.81) 0.65 (0.60-0.70) 0.021*


No 1 1

Yes 3.65 (3.29-4.04) 3.58 (3.30-3.89) 0.430


No 1 1

Yes 0.94 (0.86-1.02) 0.92 (0.86-0.99) 0.590


Setting

Citizen aimed 1 1

Hospital (incl. midwives) 1.02 (0.85-1.21) 1.09 (0.94-1.27) 0.982

Other 1.13 (0.89-1.45) 1.05 (0.84-1.31) 0.191


Programme format

Individual 1 1

Group 0.96 (0.84-1.10) 0.97 (0.87-1.08) 0.696



Free for days (<1 week) 0.87 (0.78-0.97) 0.87 (0.80-0.96) 0.199

Free for ≥1 week 0.97 (0.82-1.14) 0.95 (0.83-1.10) 0.163

Hierarchical cluster Variance (95 % CI) Variance (95% CI)


Variance of random intercepts 0.06 (0.04-0.11) 0.07 (0.04-0.11) a Disadvantaged smokers: unemployed and receiving unemployment benefits and/or low education (no education except primary schooling and/or only short

work-related courses)13

b Heavy smokers: smoking ≥20 pack-years and/or daily consumption of ≥20 cigarettes and/or Fagerström nicotine dependency score of ≥7 points

12,19

c Compliance with the programme was defined as having attended at least 75% of the scheduled meetings

17 or for Come & Quit at least 4 sessions

8

Though applying to very few patients, health promotion counselling seemed to be the most

effective intervention for men (OR=2.64; 1.21–5.71), followed by the GSP (OR=1.69; 1.27–

2.24) and other interventions (OR=1.50; 1.09–2.06). The effect of crash courses was not

significant for men. For women, only the GSP increased the effect significantly (OR=1.31;

1.03–1.68).

For both men and women, programme compliance was the most pronounced predictor of

success, and more advanced age and not being disadvantaged or a heavy smoker were other

predictors (see table 3).

An effect of the time of data collection was present, and the likelihood of remaining

continuously abstinent for 6 months was slightly higher at the start of the data collection

period (data not shown).

Page 10 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



11


We performed a non-respondent analysis of the 46,287 smokers included in the study by

comparing respondents (34,235 smokers) with non-respondents (12,052 smokers lost to

follow-up). Respondents and non-respondents were significantly different in regard to every

variable tested. The largest difference between the two groups (16.8 percentage points) was

seen in regards to compliance, where the smokers lost to follow-up were less likely to be

compliant with the programme. In addition, time of data collection, age, education,

employment, pack-years, housing situation, setting, geographic area, and planned relapse

prevention differed by more than 5 percentage points.

Another analysis performed on 82,387 smokers comparing patients not wanting to be

contacted or who were intentionally not followed up (36,100 smokers) with those who were

(46,287 smokers) showed differences of up to 8.4 percentage points. The largest difference

was geographic area, but time of collection, and planned relapse prevention also differed by

more than 5 percentage points between the compared groups.

Discussion Overall, every 3rd GSP intervention resulted in a successful outcome after 6 months.

Compared with women, men were more successful, with an additional 1 in 6 patients being

continuously abstinent. Only the GSP showed a significant result regardless of sex even after

adjusting for independent variables affecting the outcomes.

Interestingly, the short interventions seemed to be highly effective for men, while women

halved their odds of success following short interventions. For both sexes, compliance, as well

as advanced age and not being a disadvantaged or a heavy smoker were predictors of

successful quitting.

The high effectiveness of the GSP for both men and women in our study was also observed in

randomised and controlled trials evaluating the programme against typical treatments23,24. A


formats25.

Compliance was the most important predictor, increasing the odds of abstinence more than

3.5-fold regardless of sex. An earlier study showed a dose-dependent response between

compliance and continuous abstinence for GSP; the more sessions attended, the greater the

chance of succeeding17. It should be noted that compliant patients included in our study had

several characteristics that were associated with high quit rates.

In line with other studies, we found that even though women were more likely to attend a

smoking cessation intervention, they were significantly less likely to succeed than men25,26.

Bohadana et al. also confirmed these findings, which could be explained by differences in

nicotine and behavioural dependence between women and men27. Other studies have found

no differences in regards to sex28,29 or that women are more likely to quit smoking30.

Though only a few patients undertook short programmes, men showed more promising

results, while women showed significantly worse results. Brief interventions are generally

recommended, though their overall effect is low. In addition, the setting could be of relevance,

as a recent review found no effect of short interventions among surgical patients31.

Page 11 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



12

Interestingly, offering free NRT or other supportive medicine had a negative effect on

outcomes. The literature is contradictory on this matter. A recent study from England showed

no effect of free NRT in combination with a supportive quit-line for patients who wanted to

quit32. In contrast, another study found that offering free NRT increased the chances of

success significantly33. A possible explanation could be the influence of other non-individual

variables, such as the type of health system, local general dental practices or the availability of

over-the-counter drugs. Further studies are needed to clarify which group of smokers under

which conditions would benefit from free NRT.

During the study period from 2001–2013, smoking prevalence in Denmark dropped from

30% to 17% daily smokers, corresponding to 1,230–780 thousand people. Over this period,

82,431 smokers aged 15 years or older received a face-to-face smoking cessation intervention

programme registered in the SCDB, corresponding to approximately 7–11% of all daily

smokers. Converted to a yearly basis, fewer than 1% of the smokers in Denmark have

received a face-to-face smoking cessation intervention. This number is very low compared to

that of England, where 5–10% of the smokers are treated by the Stop Smoking Service29, as

well as compared to national and international guidelines recommending that 5% of all

smokers should receive a smoking cessation intervention yearly. It is difficult to compare the

present data to other countries since, to the best of our knowledge, no other countries have

clinical registers with national coverage.



continuously abstinent. Therefore, the results based on the RECORD criteria may

overestimate the quit rate when extrapolated to non-respondents. In contrast, the compliance

of patients with and without intended follow-up was more similar. Some of the differences

identified could be attributed to the large sample size. The follow-up rate was relatively high

(74%), and the large number of patients from across the country and across settings was a

strength of this study. Even though the coverage was high, the SCDB may not cover all

activities. However, only 3 of the 98 municipalities never reported to the database. SCI

activities across regions of Denmark differed more than the distribution of smokers34.

Relatively, the North Denmark Region treated fewer smokers, while the Capital Region treated

more patients than expected based on the number of smokers in each region. However, even

the most active region has treated only 0.6% of all smokers annually which is far lower than

the recommended 5%35. An additional strength was the low amount of missing data. We

addressed missing data according to RECORD guidelines20. Some of the programmes were

only recorded in the database in a limited part of the study period. Two of the programmes

only had a very low number of participants (0.3 and 0.4%) and the influence on the overall

result is therefore very limited. The programme Come & Quit was established in 2011 but

includes 3.4% of the smokers and may potentially affect the comparative analyses. However,

time for data collection only showed a minor reduction of successful quitting overtime. Thus,

the effect of the crash courses recorded only in the beginning of the period may be slightly

overestimated. We also reported continuous abstinence as the primary outcome, in contrast

to point prevalence, which has several limitations36. The self-reporting was a limitation, as

patients are likely to overestimate their success by 3–6% compared with CO-validated

outcomes37–39. We had no reason to assume that this overestimation was unevenly distributed

among the different interventions. Therefore, the groups should be comparable, even though

the quit rates may be slightly overestimated in general. Due to different cultural traditions,

Page 12 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



13

smoking habits, and socio-economic conditions, generalisations should be considered

carefully. The implications of using the routinely collected health data from the SCDB in this

study must be considered minimal, as the study is in line with the purposes of the database.

Only minor changes in data collection took place over time to include new supportive

medicine, and the eligibility has changed over time due to changes in the Danish healthcare

system16. We consider the completeness and precision of the data to be high8. We are not able

to identify possible misclassifications, but we expect their occurrence to be very low. We are

also aware of other potential confounders such as genetic predisposition, co-morbidities,

competing addictions and lifestyle factors that are not included in the analysis due to a lack of

information.

From a societal perspective, it is highly interesting that the GSP is effective across different

socio-economic groups. A systematic implementation of the GSP would therefore be highly

effective among lower socio-economic groups with the highest smoking prevalence. Only by

collecting nationwide data in a clinical database such as the SCDB is it possible to document

this important effect. Furthermore, free NRTs, other supportive medications, and self-

payment counselling did not show any association with the quit rate, in agreement with a

recent publication on financial incentives for smoking cessation40.


that should be investigated further.



indicates that smoking is associated with the development of psychosis because psychosis

develops earlier and more frequently among smokers than among non-smokers41. The high

prevalence of smoking among psychiatric patients has traditionally been interpreted as a

form of self-medication, but this has now been questioned by a meta-analysis showing that

smoking cessation improves the mental conditions of smokers with and without a psychiatric

diagnosis42.

A final area of major interest is that smoking cessation databases can be used for early

detection, i.e., to follow the effects of smoking cessation interventions across a country rather

than waiting to see the effect directly on smoking related illness and death. We recommend

that other countries establish national smoking cessation databases for these purposes and

for comparing effects between countries.

Conclusion Over time, Danish smoking cessation interventions have been shown to be effective in real

life. Ultimately, 1 in 3 smokers are still abstinent at 6 months of follow-up (or 1 in 4 if non-

respondents are judged as smokers). Compliance is the main predictor of successful quitting.

We expected to find that the GSP would be the most effective intervention, but interestingly,

short programmes also seem to have relatively strong effect among men, though the absolute

numbers are very small. Only the comprehensive standard programme in Denmark, the GSP,

works across sexes.

Page 13 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



14








Competing interests All authors have completed the ICMJE uniform disclosure form at

www.icmje.org/coi_disclosure.pdf (available upon request from the corresponding author)

and declare no support from any organisation for the submitted work, no financial

relationships with any organisations that may have an interest in the submitted work over the

previous three years, and no other relationships or activities that could appear to have

influenced the submitted work.

Data sharing Data from the SCDB are archived in The Danish Data Archive. Project descriptions,

anonymised datasets, and statistical codes used in this study are available from the

corresponding author.

All authors, external and internal, had full access to all of the study data (including statistical

reports and tables) and take responsibility for the integrity of the data and for the accuracy of

the data analysis.



MR drafted the manuscript, and EF and HT revised it critically for important intellectual

content. All of the authors gave final approval of the version to be published. HT is the

guarantor.

Copyright The Corresponding Author assumes the right to grant on behalf of all authors, and does grant

on behalf of all authors, an exclusive licence (or non-exclusive for government employees) on

a global basis for the BMJ Publishing Group Ltd. to allow this article (if accepted) to be

published in BMJ editions and in any other BMJPGL products and sublicenses and such uses

and to exploit all subsidiary rights, as set out in our licence.

Transparency declaration The lead author (study guarantor) affirms that the manuscript is an honest, accurate, and

transparent account of the study being reported, that no important aspects of the study have

Page 14 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



15

been omitted, and that any discrepancies from the study as planned (and, if relevant,






2013;380(9859):2224–60.

3. The Health Consequences of Smoking—50 Years of Progress A Report of the Surgeon General. United States Department of

Health and Human Services, 2014. (Assecced on April 25, 2016, at http://www.surgeongeneral.gov/library/reports/50-years-of-

progress/full-report.pdf).










8. Rasmussen M, Tønnesen H. The Danish Smoking Cessation Database. Clin Health Promot 2016;6(2):Accepted

9. Clinical Practice Guideline Treating Tobacco Use and Dependence 2008 Update Panel, Liaisons and S. A Clinical Practice

Guideline for Treating Tobacco Use and Dependence: 2008 Update. Am J Prev Med 2008;35(2):158–76.







13. Neumann T, Rasmussen M, Ghith N, Heitmann BL, Tønnesen H. The Gold Standard Programme: smoking cessation

interventions for disadvantaged smokers are effective in a real-life setting. Tob Control 2013;22(e9):Epub 2012 Jun 16.

14. Rasmussen M, Heitmann BL, Tønnesen H. Effectiveness of the Gold Standard Programmes (GSP) for Smoking Cessation in

Pregnant and Non-Pregnant Women. Int J Environ Res Public Health 2013;10(8):3653–66.

15. Kehlet M, Schroeder T, Tønnesen H. The Gold Standard Program for Smoking Cessation is Effective for Participants Over 60 Years of Age. Int J Environ Res Public Health 2015;12(3):2574–87.

16. Rasmussen M, Ammari ABH, Pedersen B, Tønnesen H. Smoking cessation intervention activities and outcome before, during

and after the national Healthcare Reform in Denmark. Clin Health Promot 2012;2(1):26–35.


cessation intervention: population study in Denmark. Clin Health Promot 2012;2(3):111–9.

18. Danish Cancer Association. About Kom & Kvit (Come & Quit). (Assecced on April 25, 2016, at https://www.cancer.dk/komogkvit/engelsk/)

19. Heatherton TF, Kozlowski LT, Frecker RC, Fagerström KO. The Fagerström Test for Nicotine Dependence: a revision of the

Fagerström Tolerance Questionnaire. Br J Addict 1991;86(9):1119–27.




2005;100(3):299–303.

22. Pedersen CB. The Danish Civil Registration System. Scand J Public Health 2011;39(7 suppl):22–5.

23. Møller AM, Villebro N, Pedersen T, Tønnesen H. Effect of preoperative smoking intervention on postoperative complications: a

randomised clinical trial. Lancet 2002;359(9301):114–7.

Page 15 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



16





26. Martínez C, Martínez-Sánchez JM, Ballbè M, et al. Smoking cessation in hospital workers: effectiveness of a coordinated

program in 33 hospitals in Catalonia (Spain). Cancer Nurs 2012;35(5):327–36.



28. Puente D, Cabezas C, Rodriguez-Blanco T, et al. The role of gender in a smoking cessation intervention: a cluster randomized clinical trial. BMC Public Health 2011;11:369.

29. Dobbie F, Hiscock R, Leonardi-Bee J, Murray S, Shahab L, Aveyard P. Evaluating Long-term Outcomes of NHS Stop Smoking

Services (ELONS): a prospective cohort study. Heal Technol Assess 2015;19(95).



31. Thomsen T, Villebro N, Møller AM. Interventions for preoperative smoking cessation. Cochrane database Syst Rev 2014;3:CD002294.

32. Ferguson J, Docherty G, Bauld L, et al. Effect of offering different levels of support and free nicotine replacement therapy via an

English national telephone quitline: randomised controlled trial. BMJ 2012;344:e1696.









Suppl:59–69.


Suppl:46–58.



40. Halpern SD, French B, Small DS, et al. Randomized trial of four financial-incentive programs for smoking cessation. N Engl J Med 2015;372(22):2108–17.





Page 16 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Figure 1: Descriptions of smoking cessation interventions examined in this study. Figure 1

173x158mm (300 x 300 DPI)

Page 17 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Figure 2: Flowchart. In total, 82,515 smokers were registered in the SCDB and 36,228 were excluded, leaving 46,287 smokers in the study population. Of them, 26% of the study population were lost to follow-

up, leaving 34,235 smokers included in the outcome analyses

Figure 2 98x55mm (600 x 600 DPI)

Page 18 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Appendix

Non-respondentanalyses:Losttofollow-up.


Participants

. tab2 r_method FollowUp06, chi2 column missing

Pearson chi2(6) = 1.4e+03 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 9.45 19.88 12.16 2012-2013 3,234 2,396 5,630 13.02 17.60 14.21 2010-2011 4,458 2,121 6,579 19.03 18.32 18.84 2008-2009 6,514 2,208 8,722 17.67 17.54 17.64 2006-2007 6,049 2,114 8,163 19.79 14.31 18.36 2004-2005 6,774 1,725 8,499 17.25 10.27 15.43 2002-2003 5,906 1,238 7,144 3.80 2.07 3.35 2001 1,300 250 1,550 collection Follow-up No follow Total data 6-month follow-up Time of

Pearson chi2(4) = 239.6633 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 7.73 8.93 8.04 Other 2,645 1,076 3,721 2.80 5.24 3.44 Come and Quit 960 632 1,592 0.46 0.20 0.40 Speed courses 159 24 183 0.21 0.57 0.30 Brief Intervention 71 69 140 88.80 85.06 87.82 GSP 30,400 10,251 40,651 intervention Follow-up No follow Total Method/Type of 6-month follow-up

Pearson chi2(2) = 7.5703 Pr = 0.023

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.01 0.04 0.02 . 2 5 7 61.20 61.04 61.16 Female 20,953 7,356 28,309 38.79 38.92 38.83 Male 13,280 4,691 17,971 Sex Follow-up No follow Total 6-month follow-up

Pearson chi2(5) = 553.5021 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.20 0.40 0.25 . 69 48 117 36.30 30.38 34.75 55+ years 12,426 3,661 16,087 27.24 24.78 26.59 45-54 years 9,324 2,986 12,310 20.46 20.94 20.59 35-44 years 7,006 2,524 9,530 11.89 15.07 12.71 25-34 years 4,069 1,816 5,885 3.92 8.44 5.09 15-24 years 1,341 1,017 2,358 course Follow-up No follow Total of the 6-month follow-up beginning Age at the

Page 19 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Pearson chi2(2) = 96.9182 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 3.53 4.27 3.72 . 1,209 515 1,724 44.20 48.58 45.34 High education 15,131 5,855 20,986 52.27 47.15 50.94 Low education 17,895 5,682 23,577 Education Follow-up No follow Total 6-month follow-up

Pearson chi2(2) = 174.9989 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 2.30 3.18 2.53 . 788 383 1,171 16.69 21.45 17.93 Unemployed 5,715 2,585 8,300 81.00 75.37 79.54 Not unemployed 27,732 9,084 36,816 Job situation Follow-up No follow Total 6-month follow-up

100.00 100.00 100.00 Total 34,235 12,052 46,287 3.53 4.13 3.68 . 1,207 498 1,705 59.33 56.52 58.60 Disadvantaged 20,311 6,812 27,123 37.15 39.35 37.72 Not disadvantaged 12,717 4,742 17,459 disadvantaged Follow-up No follow Total Being 6-month follow-up

Pearson chi2(2) = 157.2072 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.67 1.52 1.63 . 572 183 755 66.22 60.10 64.63 ≥20 pack-years 22,672 7,243 29,915 32.10 38.38 33.74 <20 pack-years 10,991 4,626 15,617 years Follow-up No follow Total No. of pack 6-month follow-up

Pearson chi2(2) = 47.6348 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.55 0.80 0.61 . 187 97 284 26.86 29.70 27.60 7-10 points 9,195 3,579 12,774 72.60 69.50 71.79 0-6 points 24,853 8,376 33,229 score Follow-up No follow Total Fagerström 6-month follow-up

Pearson chi2(2) = 14.1003 Pr = 0.001

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.16 0.98 1.11 . 396 118 514 56.02 57.89 56.51 ≥20 cigarettes per da 19,178 6,977 26,155 42.82 41.13 42.38 <20 cigarettes per da 14,661 4,957 19,618 Cigarettes per day Follow-up No follow Total 6-month follow-up


Pearson chi2(2) = 27.8962 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.49 0.78 0.57 . 168 94 262 75.60 73.65 75.09 Heavy smoker 25,883 8,876 34,759 23.91 25.57 24.34 Not heavy smoker 8,184 3,082 11,266 Heavy smoker Follow-up No follow Total 6-month follow-up

Pearson chi2(2) = 1.1e+03 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.27 2.30 1.54 . 434 277 711 67.68 50.85 63.29 Yes 23,169 6,128 29,297 31.06 46.86 35.17 No 10,632 5,647 16,279 programme Follow-up No follow Total with the 6-month follow-up Compliant

Page 20 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from




Pearson chi2(2) = 11.8403 Pr = 0.003

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.05 1.29 1.11 . 358 155 513 35.63 34.19 35.25 Yes 12,197 4,121 16,318 63.33 64.52 63.64 No 21,680 7,776 29,456 smoker Follow-up No follow Total with a 6-month follow-up Living

Pearson chi2(3) = 14.5823 Pr = 0.002

100.00 100.00 100.00 Total 20,263 8,839 29,102 1.09 1.04 1.07 . 220 92 312 33.82 32.44 33.40 Living with adults (n 6,853 2,867 9,720 30.73 29.85 30.46 Living with children 6,226 2,638 8,864 34.37 36.68 35.07 Living alone 6,964 3,242 10,206 Living with others Follow-up No follow Total 6-month follow-up

Pearson chi2(4) = 392.5174 Pr = 0.000

100.00 100.00 100.00 Total 20,263 8,839 29,102 1.75 2.25 1.90 . 354 199 553 0.91 1.86 1.20 Other 184 164 348 39.74 49.49 42.70 Rental 8,052 4,374 12,426 8.34 9.19 8.59 Partly owned 1,689 812 2,501 49.27 37.22 45.61 Owner 9,984 3,290 13,274 situation Follow-up No follow Total Housing 6-month follow-up

Pearson chi2(3) = 248.9327 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 2.61 3.69 2.89 . 894 445 1,339 10.66 6.22 9.51 Yes, by others (not H 3,650 750 4,400 46.36 50.19 47.35 Yes, by health care p 15,870 6,049 21,919 40.37 39.89 40.25 No 13,821 4,808 18,629 by Follow-up No follow Total Reccommended to quit 6-month follow-up

Pearson chi2(4) = 130.0030 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 1.94 2.69 2.13 . 664 324 988 3.65 2.51 3.36 Yes unknown attempts 1,251 303 1,554 13.96 12.58 13.60 > 3 attempts 4,780 1,516 6,296 51.19 48.85 50.58 1-3 attempts 17,525 5,887 23,412 29.25 33.37 30.33 None 10,015 4,022 14,037 attempts Follow-up No follow Total Earlier quit 6-month follow-up

. tab2 scc_setting FollowUp06, chi2 column missing

Pearson chi2(4) = 118.9975 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 24.73 23.85 24.50 South Denmark 8,466 2,875 11,341 14.19 12.10 13.65 Region Zealand 4,859 1,458 6,317 4.76 4.73 4.76 North Denmark 1,631 570 2,201 23.83 21.68 23.27 Central Denmark 8,157 2,613 10,770 32.49 37.64 33.83 Capital Region 11,122 4,536 15,658 intervention Follow-up No follow Total Place of the 6-month follow-up

Page 21 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from




.

Pearson chi2(2) = 146.2297 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 4.60 3.59 4.34 Other 1,574 433 2,007 22.17 17.61 20.98 Hospital/Midwife 7,590 2,122 9,712 73.23 78.80 74.68 Citizen aimed 25,071 9,497 34,568 Setting Follow-up No follow Total 6-month follow-up

Pearson chi2(1) = 36.7751 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 83.55 81.13 82.92 Groups 28,603 9,778 38,381 16.45 18.87 17.08 Individually 5,632 2,274 7,906 intervention Follow-up No follow TotalFormat of the 6-month follow-up

Pearson chi2(6) = 216.0385 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.02 0.07 0.03 . 7 9 16 3.25 6.00 3.96 Other 1,111 723 1,834 2.91 2.08 2.69 Pregnant 995 251 1,246 5.98 5.27 5.80 Mixed 2,048 635 2,683 53.82 54.18 53.91 Ordinary citizens 18,425 6,530 24,955 23.66 22.67 23.40 Working place 8,101 2,732 10,833 10.36 9.72 10.20 Patients 3,548 1,172 4,720 Target audience Follow-up No follow Total 6-month follow-up

Pearson chi2(3) = 83.0809 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 7.27 7.11 7.23 . 2,490 857 3,347 12.93 13.57 13.10 Free for one week or 4,426 1,636 6,062 40.89 36.43 39.73 Free for days 14,000 4,391 18,391 38.90 42.88 39.94 No 13,319 5,168 18,487 supportive medication Follow-up No follow Total Free NRT or other 6-month follow-up

Pearson chi2(2) = 81.8218 Pr = 0.000

100.00 100.00 100.00 Total 34,235 12,052 46,287 0.08 0.17 0.10 . 26 21 47 10.35 7.67 9.65 Yes user payment 3,545 924 4,469 89.57 92.16 90.24 No user payment 30,664 11,107 41,771 User payment Follow-up No follow Total 6-month follow-up

.

Pearson chi2(1) = 80.1838 Pr = 0.000

100.00 100.00 100.00 Total 20,263 8,839 29,102 49.11 43.41 47.38 Yes 9,951 3,837 13,788 50.89 56.59 52.62 No 10,312 5,002 15,314 prevention Follow-up No follow Total relapse 6-month follow-up Planned

Page 22 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Non-respondentanalyses:smokersnotwantingtobecontactedorwhowereintentionallynot

followedupversusthosewhowere.


Participant

Pearson chi2(6) = 994.6432 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 12.08 11.86 11.99 2012-2013 5,630 4,246 9,876 14.12 12.58 13.45 2010-2011 6,579 4,503 11,082 18.72 14.55 16.91 2008-2009 8,722 5,207 13,929 17.52 19.37 18.33 2006-2007 8,163 6,935 15,098 18.63 26.39 22.00 2004-2005 8,682 9,445 18,127 15.54 12.39 14.17 2002-2003 7,239 4,436 11,675 3.38 2.86 3.16 2001 1,576 1,024 2,600 collection Followed Not follo Total data 6-month follow-up Time of

Pearson chi2(4) = 228.3708 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 8.04 11.00 9.32 Other 3,744 3,938 7,682 3.42 3.10 3.28 Come and Quit 1,592 1,108 2,700 0.40 0.58 0.48 Speed courses 188 206 394 0.30 0.28 0.29 Brief Intervention 140 100 240 87.84 85.05 86.63 GSP 40,927 30,444 71,371 intervention Followed Not follo Total Method/Type of 6-month follow-up

. tab2 b_age_cat FollowUp06, chi2 column missing

Pearson chi2(2) = 1.5447 Pr = 0.462

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.02 0.02 0.02 . 9 6 15 61.14 60.72 60.96 Female 28,484 21,736 50,220 38.84 39.26 39.03 Male 18,098 14,054 32,152 Sex Followed Not follo Total 6-month follow-up

. tab2 b_education FollowUp06, chi2 column missing

Pearson chi2(5) = 58.0022 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.27 0.49 0.37 . 126 177 303 34.66 33.60 34.20 55+ years 16,147 12,026 28,173 26.58 26.97 26.75 45-54 years 12,386 9,653 22,039 20.60 20.71 20.65 35-44 years 9,600 7,414 17,014 12.76 12.37 12.59 25-34 years 5,945 4,429 10,374 5.12 5.86 5.44 15-24 years 2,387 2,097 4,484 course Followed Not follo Total of the 6-month follow-up beginning Age at the

Pearson chi2(2) = 96.1876 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 3.72 4.41 4.02 . 1,734 1,577 3,311 45.14 41.92 43.74 High education 21,029 15,006 36,035 51.14 53.67 52.24 Low education 23,828 19,213 43,041 Education Followed Not follo Total 6-month follow-up

. tab2 b_disadvantaged FollowUp06, chi2 column missing

Pearson chi2(2) = 11.5754 Pr = 0.003

100.00 100.00 100.00 Total 46,591 35,796 82,387 2.53 2.89 2.68 . 1,179 1,033 2,212 17.87 17.45 17.69 Unemployed 8,328 6,247 14,575 79.59 79.66 79.62 Not unemployed 37,084 28,516 65,600 Job situation Followed Not follo Total 6-month follow-up

Page 23 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



. tab2 b_packyears FollowUp06, chi2 column missing

Pearson chi2(2) = 56.4533 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 3.68 4.20 3.91 . 1,715 1,503 3,218 58.77 60.61 59.57 Disadvantaged 27,380 21,697 49,077 37.55 35.19 36.53 Not disadvantaged 17,496 12,596 30,092 disadvantaged Followed Not follo Total Being 6-month follow-up

. tab2 b_nicotin_dependency FollowUp06, chi2 column missing

Pearson chi2(2) = 35.0457 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.65 2.21 1.89 . 769 792 1,561 64.52 64.42 64.48 ≥20 pack-years 30,061 23,059 53,120 33.83 33.37 33.63 <20 pack-years 15,761 11,945 27,706 years Followed Not follo Total No. of pack 6-month follow-up

. tab2 b_tobacco_consumption FollowUp06, chi2 column missing

Pearson chi2(2) = 29.4824 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.62 0.95 0.76 . 289 340 629 27.56 27.68 27.61 7-10 points 12,840 9,909 22,749 71.82 71.37 71.62 0-6 points 33,462 25,547 59,009 score Followed Not follo Total Fagerström 6-month follow-up

Pearson chi2(2) = 12.9606 Pr = 0.002

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.13 1.39 1.24 . 526 497 1,023 56.44 56.76 56.58 ≥20 cigarettes per da 26,297 20,319 46,616 42.43 41.85 42.18 <20 cigarettes per da 19,768 14,980 34,748 Cigarettes per day Followed Not follo Total 6-month follow-up


Pearson chi2(2) = 30.0704 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.57 0.89 0.71 . 267 320 587 75.01 75.00 75.00 Heavy smoker 34,947 26,847 61,794 24.42 24.11 24.28 Not heavy smoker 11,377 8,629 20,006 Heavy smoker Followed Not follo Total 6-month follow-up

Pearson chi2(2) = 593.0973 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.53 4.19 2.68 . 711 1,501 2,212 63.32 63.72 63.49 Yes 29,502 22,809 52,311 35.15 32.09 33.82 No 16,378 11,486 27,864 programme Followed Not follo Total with the 6-month follow-up Compliant

. tab2 b_living_with_others FollowUp06 if old_new==2, chi2 column missing

Pearson chi2(2) = 55.4289 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 1.12 1.63 1.34 . 521 585 1,106 35.29 36.39 35.76 Yes 16,440 13,025 29,465 63.60 61.98 62.89 No 29,630 22,186 51,816 smoker Followed Not follo Total with a 6-month follow-up Living

Pearson chi2(3) = 47.7068 Pr = 0.000

100.00 100.00 100.00 Total 29,102 20,794 49,896 1.07 1.63 1.30 . 312 339 651 33.40 33.76 33.55 Living with adults (n 9,720 7,020 16,740 30.46 31.52 30.90 Living with children 8,864 6,554 15,418 35.07 33.09 34.25 Living alone 10,206 6,881 17,087 Living with others Followed Not follo Total 6-month follow-up

Page 24 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from





Pearson chi2(4) = 128.7344 Pr = 0.000

100.00 100.00 100.00 Total 29,102 20,794 49,896 1.90 2.67 2.22 . 553 556 1,109 1.20 1.22 1.20 Other 348 253 601 42.70 39.91 41.53 Rental 12,426 8,298 20,724 8.59 6.98 7.92 Partly owned 2,501 1,452 3,953 45.61 49.22 47.12 Owner 13,274 10,235 23,509 situation Followed Not follo Total Housing 6-month follow-up

Pearson chi2(3) = 21.2984 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 2.87 2.87 2.87 . 1,339 1,029 2,368 9.60 10.53 10.00 Yes, by others (not H 4,472 3,770 8,242 47.15 46.23 46.75 Yes, by health care p 21,967 16,548 38,515 40.38 40.36 40.37 No 18,813 14,449 33,262 by Followed Not follo Total Reccommended to quit 6-month follow-up

Pearson chi2(4) = 59.8356 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 2.16 2.55 2.33 . 1,005 913 1,918 3.41 4.29 3.79 Yes unknown attempts 1,587 1,536 3,123 13.62 13.36 13.51 > 3 attempts 6,346 4,781 11,127 50.52 50.18 50.37 1-3 attempts 23,539 17,963 41,502 30.29 29.62 30.00 None 14,114 10,603 24,717 attempts Followed Not follo Total Earlier quit 6-month follow-up

Pearson chi2(4) = 1.4e+03 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 24.47 23.20 23.92 South Denmark 11,399 8,305 19,704 13.68 22.07 17.33 Region Zealand 6,375 7,900 14,275 4.76 6.44 5.49 North Denmark 2,220 2,306 4,526 23.33 22.86 23.12 Central Denmark 10,868 8,183 19,051 33.76 25.43 30.14 Capital Region 15,729 9,102 24,831 intervention Followed Not follo Total Place of the 6-month follow-up

.

Pearson chi2(2) = 102.0653 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 4.35 5.84 5.00 Other 2,026 2,090 4,116 21.00 21.44 21.19 Hospital/Midwife 9,784 7,675 17,459 74.65 72.72 73.81 Citizen aimed 34,781 26,031 60,812 Setting Followed Not follo Total 6-month follow-up

Pearson chi2(1) = 121.6374 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 82.97 79.97 81.66 Groups 38,655 28,625 67,280 17.03 20.03 18.34 Individually 7,936 7,171 15,107 intervention Followed Not follo TotalFormat of the 6-month follow-up

Page 25 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from



Pearson chi2(6) = 119.5273 Pr = 0.000

100.00 100.00 100.00 Total 46,591 35,796 82,387 0.03 0.04 0.04 . 16 14 30 3.97 4.75 4.31 Other 1,848 1,702 3,550 2.69 3.08 2.86 Pregnant 1,255 1,103 2,358 5.79 6.80 6.23 Mixed 2,697 2,434 5,131 53.81 52.36 53.18 Ordinary citizens 25,069 18,742 43,811 23.53 21.90 22.82 Working place 10,963 7,841 18,804 10.18 11.06 10.56 Patients 4,743 3,960 8,703 Target audience Followed Not follo Total 6-month follow-up

Page 26 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



jopen.bmj.com

/B

MJ O


ebruary 2017. Dow

nloaded from





Item

No.


manuscript where

items are reported


manuscript

where items are

reported

Title and abstract







what was found












or abstract.

Done – page 1

Done (abstract) –

page 2

Not relevant – no

linkage

Introduction

Background

rationale



being reported

Done – page 4



hypotheses

Last paragraph in


Methods



Done – page 4





See Study design,



6




Data – page 5-6



Done – page 5-6

Page 27 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960






of follow-up










of participants




unexposed




case

Not relevant




provided.













Not relevant

Not relevant






See Outcomes –

page 6-7-8






should be provided.

See table 2


page 7-8

Data sources/

measurement




(measurement).



more than one group

See Outcomes –

page 6-7-8





12

Page 28 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960





arrived at

Figure 1: Flowchart

– page 6

Quantitative

variables





and why

See Outcomes –

page 6-7-8

Statistical

methods






interactions


were addressed



was addressed




addressed




sampling strategy


analyses

See Statistical


Data access and

cleaning methods





population.




See Data Access

and Cleaning –

page 9



Not relevant - no

linkage

Page 29 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960








Results







and analysed)




diagram

Figure 1: Flowchart

– page 6









See Figure 1:

Flowchart, and

results (1th

paragraph text on

missing values) –

page 6+9





confounders






total amount)

See table 2, and

results (1th

paragraph text on

missing values) –

page 7-8+9



measures over time




of exposure



summary measures

Done – page 10


Page 30 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960












categorized





Abstinence

(Included based on

preliminary



8

Not relevant




analyses

Non-respondent


Discussion



Beginning of








12









Paragraph 8 in

discussion – page

12







evidence

Paragraph 9-13(-17)

– page 12-13



results


13

Page 31 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960




Other Information






Acknowledgements

– page 14

Accessibility of

protocol, raw

data, and

programming

code





programming code.

Data sharing (after

acknow-

ledgements) –

page 14



in press.


Page 32 of 32


BMJ Open

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960



BMJ Open€¦ · For peer review only 16 15. Kehlet M, Schroeder T, Tønnesen H. The Gold Standard...

Documents

Transcript of BMJ Open€¦ · For peer review only 16 15. Kehlet M, Schroeder T, Tønnesen H. The Gold Standard...