Scottish validation study of Cancer Registration data childhood leukaemia 1968-1981--I.

This study attempted to validate central registration data on all childhood leukaemia cases in Scotland between 1968 and 1981 in line with the Black Enquiry concerning West Cumbria. Missing files precluded a complete verification, but minor errors of registration were found in 44% of cases. A small number of important mistakes of omission (eight cases), wrong diagnosis (six cases) and postal code errors (nine cases) were found which might affect epidemiological studies of these relatively rare diseases. Precise and verified prospective data collection at the time of diagnosis is essential if the spatial distribution of childhood cancers is being studied.