Dr Heather O Dickinson My web page Department of Child Health University of Newcastle My web page...

Dr Heather O DickinsonMy web pageDepartment of Child HealthUniversity of Newcastle

Audit of cancer registrations notified by National Health Service Central

Register in England & Wales

I work on the epidemiology of children’s cancer, mainly on cohort studies in relation to exposures around birth:

Heather Dickinson

population mixing infections father’s preconceptional irradiation

Learning objectives - understand:importance of ascertainment of cases from multiple sources importance of diagnostic reviewage - cohort effects

Performance objectives - able to:use capture-recapture methodsorganise a diagnostic review

12 regional cancer registries

National Health Service Central Register (NHSCR)

Cancer registration system in England & Wales

No.

of c

ance

rs

Year of diagnosis

Notified by NHSCR Expected

1971 1975 1980 1985 1990 19930

20

40

60

80

100

Cancers notified by NHSCR

Accuracy of diagnosesWere site and type codes correct?

Completeness of ascertainmentDid they tell us about ALL the people who got cancer?

ObjectiveFor NHSCR cancer registrations, 1971-89, to assess:

Accuracy of diagnostic codes from

NHSCR

Identify hospital of diagnosis

Request biopsy, pathology or post-mortem report

Request clinical records

Review cancer or death registration

Material found and satisfactory?

Hospital ID no. known?

Clinical records obtained?

Yes

Yes

Yes

No

No

No

Reviewcomplete

Pathology review of NHSCR cancer registrations

METHOD OF REVIEW n (%)Biopsy 413 (60)Pathology report 68 (10)Post-mortem report 13 (2)Clinical records only 128 (19)Cancer/death registration 66 (10)TOTAL 688 (100)

Diagnostic groups

we used 13 standard groups for children’s cancerKramarova et al., 1996

we added 3 groups for adult cancer

We grouped the cancers into diagnostic groups:

LEVEL OF AGREEMENT n (%)Complete agreement in siteand type codes

262 (38)

Agreement in diagnostic groupbut not in site and type codes

378 (55)

Disagreement in diagnosticgroup

47 (7)

TOTAL 688 (100)

Level of agreement between diagnostic codes of NHSCR

and review

Reasons for disagreement

REASONS FOR DISAGREEMENT n (%)Failures in data capture andcoding by NHSCR

19 (3)

More or less specific diagnosisthan NHSCR

5 (1)

Different diagnosis 23 (3)TOTAL DISAGREEMENTS 47 (7)

age how recently the original diagnosis

was made

Reasons for disagreementWe were interested in whether the accuracy of diagnosis depended on:

Tota

l no.

in c

ohor

t

Year1971 1975 1980 1985 1989

0

50,000

100,000

The Cumbrian birth cohort

0-14 yrs15-24 yrsover 25 yrs

0

4

8

12

0-14 15-24 over 25Age (in years) at diagnosis

% o

f cas

es

NHSCR and review diagnoses in different groups

p for heterogeneity = 0.03

0

4

8

12

1971-74 1975-79 1980-84 1985-89Time period of diagnosis

% o

f cas

es

NHSCR and review diagnoses in different groups

p for trend = 0.07

Completeness of ascertainment by NHSCR

Did NHSCR tell us about all the people in our cohort who got

cancer?


*N = No. of cancers not notified by NHSCR

SOURCE OF NOTIFICATION Age (yrs) N*Children’s Cancer Registries:

Region A 0-24 34Region B 0-14 1National 0-14 18

Cancer Bureaux:Region A 15+ 18Region B 15+ 1

NHSCR death registrations All ages 14


720 cases notified by NHSCR 694 confirmed as malignant

740 malignancies notified from all sources

Ascertainment = 694/740 = 94%

% o

f cas

es m

isse

d


p for heterogeneity = 0.02

0-14 15-24 over 25Age (in yrs) at diagnosis

0

4

8

12

0

2

4

6

8

1971-74 1975-79 1980-84 1985-89

% o

f cas

es m

isse

d

p for trend = 0.83Time period of diagnosis



Other cases? Not notified by NHSCR

AND Not notified by any other

source

Notified by NHSCR?Yes No

Notified Yes 215 11by other sources? No ?

Cases not notified by NHSCR or other sources

Over 25 years

86




15 - 24 years

24




0 - 14 years

86

Cancers missed by NHSCR Notified by

other sources? TOTALAge

at diagnosis YES NO n (%)

0-14 20 0.0 20.0 (10%)15-24 15 1.9 16.9 (7%)

over 25 11 4.4 14.4 (5%)ALL AGES 46 6.3 51.3 (7%)

(in years)

Summary: completeness of ascertainment by NHSCR

NHSCR definitely missed 46 (6%) out of 740 cases notified by all sources.

NHSCR probably missed more cases which were not notified to us by any source.

NHSCR missed 10% of cases in the youngest age group.

NHSCR probably missed at least 10% of cases in other age groups too.

Summary: completeness of ascertainment by NHSCR

Conclusions Ascertainment from multiple sources & Diagnostic review

are essential for epidemiological studies of cancer

Dr Heather O Dickinson My web page Department of Child Health University of Newcastle My web page...

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