Validity of Cancer Registry Data for Measuring the Quality of Breast Cancer Care

Background: Various groups have called for a national sys-tem to monitor the quality of cancer care. The validity of cancer registry data for quality of cancer care has not been well studied. We investigated the validity of such informa-tion in the California Cancer Registry. Methods: We com-pared registry data associated with care with data ab-stracted from the medical records of patients diagnosed with breast cancer. We also calculated a quality score for each subject by determining the proportion of four evidence-based quality indicators that were met and then compared overall quality scores obtained from registry and medical record data. All statistical tests were two-sided. Results: Re-cords of 304 patients were studied. Compared with the medi-cal record data gold standard, the accuracy of registry data was higher for hospital-based services (sensitivity = 95.0