ESTABLISHING BASE-LINE DATA IN CANCER REGISTRATION IN NORTHERN ENGLAND - IMPLICATIONS FOR HEALTH-OF-THE-NATION TARGETS

Objective - To assess the completeness and accuracy of cancer surveill ance data relevant to Health of the Nation targets. Design - A compari son of locally ascertained data on cancer with recorded cancer registr y sources in selected diagnoses. Setting - The district of South West Durham within the Northern Regional Health Authority. Patients - All p atients with lung, skin, and malignant cervical cancer who were reside nt and diagnosed in the district or identified in the Northern Region Cancer Registry during the calendar period 1989-91. Main results - Of 544 cases of cancer identified from all available sources, 448 (95.8%) were registered, ranging from 93.9% for malignant cervical cancer to 96.7% for skin cancer. In 448 cases which were both identified locally and registered, 53 (11.8%) showed disagreements between local sources and register data, involving classification of site and timing of reg istration. Twenty three cases were identified locally but were not reg istered, 22 registered but not identified locally, and 51 registered w ith the casenotes missing locally. Conclusions - Any real achievement of Health of the Nation targets may be masked by changes over time in the accuracy and completeness of information systems. In assessing the achievement or otherwise of targets, it is important to be aware of a ny differences in the completeness and accuracy of the baseline data c ompared to future measurements.