Accuracy and completeness of the registration of childhood leukaemia in The Netherlands, 1989-1992.
In the Netherlands, childhood leukaemia is recorded by the Dutch Childhood Leukaemia Study Group (DCLSG, set up in 1972) and by nine regional cancer registries which together form the Netherlands Cancer Registry (NCR, set up in 1989). The data files from the incidence years 1989-1992 of the two registries were linked in order to evaluate accuracy and completeness and to calculate and equalise the incidence rates for childhood leukaemia in The Netherlands. Unlinked records or records with disagreements (birth date, sex, type of leukaemia and incidence date) were checked by the DCLSG and by the regional cancer registries. The DCLSG recorded 431 cases of childhood leukaemia, while the NCR recorded 434 cases. After record linkage and review of the cases, it was concluded the 445 records should have been recorded as childhood leukaemia. The NCR had recorded 425 of the 445 correct cases (95.5%), but had missed 20 cases (4.5%). The DCLSG had recorded 431 of the 445 correct cases (96.9%) and had missed 14 cases (3.1%). In addition, the NCR had recorded 9 cases incorrectly as childhood leukaemia. Part of the disagreement was caused by differences in coding rules (definition of non-Hodgkin's lymphoma (NHL) and the myelodysplastic syndrome versus leukaemia). It could be concluded that the quality and completeness of the two registries was very high. Regular comparison of the recorded data will help to reveal the inherently problematic disagreement between definitions and coding.
Schouten
L J
LJ
Netherlands Cancer Registry (NCR), Association of Comprehensive Cancer Centres, Utrecht, The Netherlands.
Van der Does-van den Berg
A
A
Otter
R
R
Coebergh
J W
JW
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual / Q000592:standards; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology*; D012042:Registries / Q000592:standards*; D012680:Sensitivity and Specificity