Health services based trials (HSB): introductory course Elina Hemminki THL, Universities of Helsinki...

Post on 17-Dec-2015

214 views 0 download

Transcript of Health services based trials (HSB): introductory course Elina Hemminki THL, Universities of Helsinki...

Health services based trials (HSB): introductory course

Elina HemminkiTHL, Universities of Helsinki and Tampere(National Institute for Health and Welfare)

Helsinki May 11,12,18 2009Department of Public Health, Helsinki

Structure of the course

Monday 11, Elina Hemminki• Introduction of participants and interests• Introductory lecture• Assignment of group/ individual work• Start of group/ individual workTuesday 12, Diana Elbourne, Nea Malila,

Minna KailaMonday 18, student presentations• presentations + discussion• what next

Volume and credits

Guided work 12 hoursIndependent work 10 hours• reading and commenting an article• project plan (shared work)• course diary (a brief description what you

learnt/ wondered of the lectures or the topic)

Credits (to be clarified): if all of the above: ..credits.

If 60-90%: ..credits

Outline of the introductory lectur

• Trials: Experimental vs non-experimental

• Various kinds of trials

• HSB: why, features

• Examples

Material:

• 3 papers for exercise 1

• Others which may be of interest

• List of further reading (later)

• Copies of presentations

Trials: Experimental vs non-experimental

1. Introduction

2. Doing a trial

3. Difficulties

4. Additional issues

5. Impact of trials

6. Exercises

What does a trial mean?

• Intervention to group(s), created by the researcher (><natural trials)

• Usually, two or more (>< uncontrolled trial)

• Good trials: comparable groups (same calendar time)

• Most common allocation method: randomization (why: also unknown predictors)

• Different kinds of trials

History

• First modern clinical trial 1940s (TB and streptomycin, MRC in UK)

• blood letting, scurvy and vitamin C

• later non-clinical health trials

• agriculture etc earlier

• www.jameslindlibrary.ccccc

Why trials?

• Unbiased information

• Especially important in case of therapy and other intentional activities (selection bias)

• “All new interventions in health care (and those old not previously studies) should be introduced via trials”

• Simple in theory, difficult in practice

Advantages

• With an example

• postmenopausal hormone therapy

• used for decades based on non-experimental data

• millions of women exposed for a preventive therapy; health (and monetary) costs large

HT

• (Female) hormone drug therapy during and after menopause, HRT

• Estrogens (+ progestins + other), extracts, DES, other synthetic

• 80 yr + for symptoms

• 40 yr + against aging

• 30 yr + for preventing diseases (all major chronic diseases)

• North America (USA) --> Western & Northern Europe --> whole world

1980 1984 1988 1992 1996 20000

10

20

30

40

50

60

DDD/1000 inhab.

Year

Finland

The Nurses’ Health Study

121,700 females age 30-55 in 1976-1994, risk of cardiovascular deaths .

OR (95% Cl)

Never Current HRT Past HRT use

Crude 1.0 0.35 (0.25-0.49) 0.84(0.67-1.05)

Adjusted 1.0 0.47 (0.32-0.69) 0.99 (0.75-1.30)

NEJM 1997;336:1769-75

WHI, Women’s health initiative

• 16 000 ”healthy” women; RCT, 8 yr prevention of cardiovascular diseases

• stopped after 5 yr: ineffective, harms

• 7 extra heart infarcts per year per 10 000 women

• 8 extra breast cancers

• 8 extra brain insults

• 18 extra deep vain thrombosis

WHI, Women’s health initiative

• less fractures

• less colon cancer

• (no major effect on metabolic diseases, dementia, well-being)

Other trials

• Nachtigall et al. 1979: +

• Hemminki et al. 1997: ?

• HERS 1998: -

• Interim report from WHI 2000: 0

• (WHI 2002: -)

• WH1-2 2004: -

Small secondary prevention trialsEVTET 2000: -

WEST 2001: 0

PAPWORTH 2002

ESPRIT 2002

etc.(Michels ym 2003)

Why a difference in observational and experimental studies?

• several papers trying to solve what was the cause.

• an explantion (of general relevance: bias9

Bias in observational studies of Oestrogen and Heart Disease

Source Effect on OR

Prescribing bias decrease

More educated decrease

Higher social class decrease

Osteoporosis decrease

No disease* decrease

Healthier decrease

Compliance decrease* diabetes, hypertension, cardiovascular

After Barrett-Connor, BMJ 1998; 317:457-461

CDP- RCT; secondary prevention of CHD, clofibrate,Males 30-60 (n=2789)

5 yr Mortality, Placebo Group Adjusted

for 40 baseline

characteristics

67% “GOOD” ADHERERS* 15 % 16 %

33% “POOR” AHDERERS 28 % 26 % Adjusted OR death =0.64 attributable tocompliance

* > 80 % prescribed doseNEJM 1980; 303: 1038-1041

Doing a trial

Doing a trial: Simple in theory, difficult in practice

• Dependent on others (service providers, customers, politicians, press etc) /laboratory, archives, interviews

• On line research, things are changing while research is going on, a moving train

• Ideological opposition, “guinea pigs “

• Costs, bureaucracy

• Researcher skills/ administrative skills

General principles

• Forward in time, like a cohort study

• Define the intervention

• Create the groups

• Expose them to intervention(s)/ control

• Define the outcomes, measure them,

• Compare the groups

Forward in time

• like a cohort study

• starting from exposure (intervention)

• parallel in time; cross-over-design

______________

• uncontrolled trials: “comparison” group may be the situation before or after; I do not recommend

Define the intervention

• Important to be explicit

• how feasible? Original and compromised

• how applicable after the trial?

• together with those who implement

• think all elements, including the soft ones

• describe the intervention in detail

• monitor whether the intervention is as planned; report changes; correct if possible

Create the groups

• Target population (different for mechanistic and practical trials)

• Allocation: randomization if possible (takes care also unknown confounders)

• Unit: an individual, a department, a village• Power calculations: how many ---> impact

on all aspects of the study• Power calculations different for individual

and cluster trials• What is possible?

Expose to intervention(s)/ control

• Craftsman skills: weak link often

• Method and skills needed: depends on the intervention and context

• Contamination (control group)

Define outcomes, measure them • Mechanistic vs. practical: to understand

what happens/ is the intervention useful

• Often: too much intermediary, laboratory, process etc. outcomes

• Too little health, unanticipated outcomes

• Costs of intervention (important for decision)

• Costs of data collection

• An issues: How much determined by data source

Compare the groups

• Simple if groups similar (randomized and large numbers): “cross-tabulations”

• Analysis by intention to treat (compliance, drop-outs)

• Main outcomes such that data from everyone possible to get

• Sub-analysis by compliance etc

• Overall outcome from all dimensions (for decision making)

Typical challenges or problems

• providers/ others responsible

• balance between feasibility and generalizibility

• changes in environment, time (too early/late)

• compliance, dilutation

• drop-outs, loss to follow-up

• costs and dependence on financiers

Persuasion of service providers/ others responsible

• Skills not often trained, nor typical for researchers

• Conflicting interests; knowing the politics and march order

• Routines help, others’ experiences

• Unconventional approaches or challenging current practices: ?

• Shopping around (Researcher X moved to town Y because it had good chief physician)

Balance between feasibility and generalizibility

• Generalizibility: can the results of the trial be transferred to practice/ other contexts?

• Often a compromise what would be best and what can be done

• Stepwise

• Using other type of evidence to fill the gap between own trial and the practice

Changes in environment, time

• “It is too early to study an intervention until it is too late”

• “The results of trials tell about history”

• Environment may change (political, administrative, health, services, public perception, funding…, CHIMACA)

• Competing groups may publish their results (WHI and Wisdom)

• A problem especially with long-term exposures/ follow-ups

Compliance, dilutation

• Trial participants do not do as planned

The groups start resembling each other.

Control group wants; intervention does not want.

• Especially important for trials when

- intervention based on behavior changes

- long term intervention

- hot topic

Drop-outs, loss to follow-up

• How serious threat: depends on the context and the intervention; long follow-up

• Anticipation: is there a way to get at least some information from all

• Compromises in terms of other aspects (e.g. comprehensive information)

• Routine record keeping / special data collection

• Drop from intervention/ from data collection

Costs and dependence on financiers

• Cost-efficiency of the trial

• Costs of the study an aspect in all methodological decisions

• Bias in topics by the interest of potential financiers

• Service providers should be responsible: trials a part of routine services (see Chalmers papers)

Practical issues

• Permissions (ethics, data protection etc)

• Insurance, liability

• Intervention = drug: international detailed rules

• Data collection: simple/ many aspects, administrative data (register based trials)

• Financing/ time (which first: field or money?)

Difficulties

• Depends on the intervention and the design

• Mechanistic vs. practical vs HSB

• Imagination in the design may help

• Teaching of clinicians/ others responsible for activities studied

• Public relations, press

• Will be easier in the future?

• EU and drug trials

What have I learnt?

• Have several research questions (vs Peto)

• Visit field frequently; make space for finding problems (as it is vs. it should be)

• Be ambitious, but do not expect success

• Have imagination

• Look for interest groups’ motives

• Need for PR and alliances

• Find practical tips from previous research

Impact of trials

• Valued in medical literature

• Cochrane collaboration

• Other meta-analyses

• Trial registration, trial reporting rules all trials, regardless of results should be published

• “Negative” vs. “positive” results

Impact on practice

• ?

Like any research:

• “if winds are favorable “

• if key-people are involved

• if (financial) interests/ incentives

Optimistic: with time the impact will come

_______

Example of HT trial

HT sales in USA after publishing WHI-I-trial 2002

• 40 % reduction in sales of all estrogen-progestin pills July - October (prescriptions)

• 56 % in sales of Prempro®

• competing drugs: a small increase

Source: The Associated Press, November 2002 (web)

HT myynti Suomessa 1980-2004

HT use in Estonia and in Finland

0

10

20

30

40

50

60

DDD/

1000

inha

bita

nts

Comments of WHI-I trial in Finnish medical journals

Not so enthusiastic

• Important 7 / 13

• One of many 4

• Not for preventing CVD 5

Possible reasons for Finnish physicians’ defensive position

• fear of loosing personal credibility (experts)

• fear of loosing professional credibility (among patients and lay-persons)

• too much at stake in clinical work

• too much at stake research wise

• education and push from competing firms

Pragmatic vs explanatory trials, mechanistic vs practical

• Originally by Schwartz and Lellouch 1960s

• Criteria changed but basic idea the same: two types of trials at the end of the continuum

• Impact on all phases

• Simplified: practical brings answers for practice; main problem in generalization

Outline for HSB-trials

• What HSB is and why it is important?

• Do HSB trials need promotative actions?

• Is Finland the promised land of HSB?

• Examples

What does "HSB trial" mean?

• The purpose is to find, through experimental research, the best form of action in health services*

• It aims for practice

* in a broad sense, including activities outside health services aiming at promoting and preserving health, treating diseases, rehabilitation and (medical) nursing

Terms in Finnish

• kokeelliset tutkimukset terveydenhuollossa (KTT)

• terveydenhuoltoon upotetut kokeet

• terveydenhuollon interventiot

• kokeelliset tutkimukset terveydenhuollon käytännössä

• kokeelliset tutkimukset osana terveyden-huoltoa

• jne.

Terms in English• health services based trials (HSB)• complex interventions (Elbourne)• community trials• interventions in health care• social experiments • cluster (randomized) controlled trials• randomized field tests + quasi-experiments

(methods other than randomization to allocate groups)

• randomized social experiments• field experiments• trials for policy research

Typical features 1

• Experimental research = health/ health care intervention is given/ received in such a way that different groups can be reliably compared. The researcher decides grouping.

• HSB-trial definition is overlapping with other experimental trials and evaluation research.

• Classifications are continuums.

Typical features 2• Explanatory/ mechanistic trials: individual

randomization, informed consent, researchers responsible for intervention, new exposures

• HSB-trials: cluster randomization/ other allocation, no informed consent, "system" responsible for intervention, exposures already in practice

• Natural experiment: allocation independently from research, no permission, "system" responsible for intervention, exposures old or new

• Practice change: no group allocation (usually before-after), no permission, "system" responsible for intervention, exposures old or new

Typical features 3Explanatory trial

Permission: from target group

Intervention: researcher

Payer: research financer

Target group: feasibility, informativness

Results: specific (placebo a problem)

Applicability: Effect in ideal circumstances

HSB-trial

more generalhealth care systemhealth care(future) target

all effects (trial effect problem)

effect in practice

Typical features 4

• Allocation: often other than (individual) randomization

• Unit: often collective (institution, group, community) rather than a person or her part (ear, eye, leg, arm)

• applicability important (generalizibility sure only for the population studied)

Why HSB-trials are important?An addition to traditional trials

The key-tool for evidence based medicine is RCT

In their current form, RCTs (individuals as units) best suit for studying (single) technologies in selected populations

Currently, information is lacking of:

1. impact of technologies in practice

2. systems, packages, treatment strategies

Why HSB should be facilitated?

This far few HSB-trials

Likely important for evidence based health care (judged from the impact of RCTs)

Some hindering factors which could be changed

Facilitating factors

• Need for evidence based health care

• Coverage with evidence/ only in research - development (big health care payers, USA, UK)

• Increasing health care costs

• Finnish public health care system

• Research valued by service providers

• Well-educated population

• Good health registers

Hindering factors 1

• Researchers’ visions, know-how, attitudes• costs• research norms and laws

Visions and know-how. Only few trials this far --> not an established research tradition, "Have not thought of“, “Is real research”: teaching (this course).

Costs may be lowered by

1. Integrating research into normal services

2. collecting outcome data from routine records, e.g. registers

Hindering factors 2

Research regulation needs change to allow HSB-trials and proper ethical evaluation, both within Finland and internationally.

A key issues: informed consent (from who, should it be asked)

E.g.: giving health education, offering screening, organizing services, changing environment

Finnish HSB trials• Cancer screening trials (Hakama et al) Malila

• EBMeDS (supported decision making in health centers) Kaila

• LATE (quality in health centers)

• Yhteispeli (well-being of school-children)

• Isolation in psychiatric care ?

• Psychically ill parents' children (Solantaus)

• Young men at risk of marginalization (Stakes)

• Hospital discharge practices (Marja-Leena Perälä)

• Vaccination trials (KTL)

• Anti-smoking intervention among youth (KTL)

• Ergonomy in kitchens (TTL)

• Employment paths (TTL)

• Promotion of sexual health(KTL)

Register based trial on birth education

Elina Hemminki, Kaija Heikkilä, Tiina Sevon, Päivikki Koponen

Hemminki et al 2008, BMC Health Services Research 8:126 (tabled)

Childbirth classes 1• 20 maternity centers in Helsinki matched

for pairs and randomly allocated to intervention and control.

• Intervention: further education to nurses and leaflets to mothers

• Outcome: mode of delivery• Data collected from registers• Childbirth classes: an existing program• Responsibility of municipalities to organize

and finance; content not defined

Childbirth classes 2• Called research originally; by the advice of

service providers (administration) divided into program (intervention) and research (data collection).

• Design: to guarantee data with small money (routine registers)

• Maternity centers invited by service administrators and researchers

• Invitation to the head nurse of each district with letters and phone calls; personal contacts by a midwife researcher

• sent to be handled in ethics committees; did not succeed (rules did not apply)

Childbirth classes 3For• researchers received administrative back-

up from the city health administrators• no press coverageAgainst• lack of research administration rules• reluctant service providers (public health

nurses) >< competition between midwife and nurse professions

• No request from women

Childbirth classes 4

• No protest on only half of the centers being exposed

• Reluctance of the field (not felt important)

• Professional battle

Which rules apply?

Medical research or developing health care?

Is approval from ethics committee needed?

Meetings and discussions with City health planners, people responsible for developing maternity health centres

The body coordinating research activities within Helsinki city health services (TUTKA)

Helsinki University coordinating ethics committee

Gynaecology and obstetrics committee

TUTKA: “Development project, no ethics committee statement is required”

KIVA school trial

• Financed by the Ministry of Education, Turku University, Cristina Salmivalli

• Developing a program to prevent bullying at school grades 1-3, 4-6, 7-9, evaluating it, 2006

• "HSB": Program first introduced to 117 schools; how allocated to intervention and control? What are outcome measures?

• All Finnish schools can get the intervention autumn 2009

• KiVa Koulu web-pages: the trial is difficult to identify (hidden), not in English

Problems in law and rules

Sir Bradford Hill 1963: "there is no one way of doing clinical trials ethically, and giving detailed advice as if there were, will harm both research and ethics". BMJ 1963, 5337: 1043-9

Key actors 1: ethics committees

• one of the gate-keepers: what can and cannot be made

• starting point: participant protection• time and cost implications on research; no

responsibility to research financers• human rights --> scientific content• ethics --> surveillance of law and rules• committees over-do (protection) and

under-do (motives for research) • no "formal decision" --> no easy appeal

Relation between research and service

• different criteria for research and routine care (accepted technology)

• easier to use without research than to start with research (time, money, know-how, rewards) --> care experiments

• "I need permission to give a drug to half of my patients, but not to give it to all of them" (Richard Smithells)

Exercise 1

Read the 3 indicated papers.

Select one, write 1 page (spacing 1) what (new) you learnt, what you agree/ disagree/ wonder.

Send it to me, latest on Sunday 17 evening by e-mail

Exercise 2• Two people together (if not even, one 3 people)• Select one topic of the list or choose your own;

let me know on Tuesday your topic + who form a pair.

• Prepare a presentation for next Monday, either a power-point or a paper to be distributed, 10 min

• Divide the work among yourself, discuss the plan, present it.

• Focus: population, unit, allocation, implementation, outcome measures, data collection, costs, payer, actors, permissions

• Be prepared to comment other people’s presentations.

Exercise 2 topics

1. Can health education to school-children by ordninary health services reduce use of sweets (candy, soft drinks, cookies..)?

2. Does it matter if .. (päivystys) in health centers is done by regular physicians or outsider firms (reppufirmat)?

3. Is it better to run maternity centers combined to child wellfare centers or to family planning.

4. Can use of psyvchotropic drugs among old in institutions be prevented by adding social activities