EVALUATING FALSE POSITIVES IN 2 HOSPITAL DISCHARGE DATA SETS OF THE BIRTH-DEFECTS MONITORING PROGRAM

The principal goal in this study was to quantify false positives in th e hospital discharge data of the Birth Defects Monitoring Program cond ucted by the Centers for Disease Control and Prevention. The two hospi tal data processing agencies which contribute data to the Birth Defect s Monitoring Program, the Commission on Professional and Hospital Acti vities and the McDonnell Douglas Health Information Systems, had respe ctive levels of false positives of 13.2 percent and 8.5 percent, level s which were statistically different from each other. These false posi tive levels should be considered minimal because these data bases do n ot include information on sick babies who may be transferred into or o ut of member hospitals, and who may have their initial diagnoses signi ficantly modified. Potential correlates of false positives were evalua ted, including hospital size, diagnostic certainty, race, sex, and ins urance source. Two-thirds of all false positives were due to the misco ding of correctly diagnosed anomalies, and another quarter were clearl y contradicted in notes easily available before the patients were disc harged. The authors hope that this study of false positives will enhan ce the interpretation of the Birth Defects Monitoring Program data and lead to improved understanding of data collection and processing.