Validation of self-reported chronic conditions and health services in a managed care population

Background: Self-reported data are commonly used to estimate the prevalence of health conditions and the use of preventive health services in the population, but the validity of such data is often questioned. Methods: The Behavioral Risk Factor Survey (BRFS) was administered by telephone to a stratified, random sample of health maintenance organization (HMO) subscribers in Colorado in 1993, and self-reports were compared with HMO medical records for 599 adults aged >21. Sensitivity and specificity were calculated for three chronic conditions and use of six preventive services. Results: Sensitivity was highest for hypertension (83%), moderate for diabetes (73%), and lowest for hypercholesterolemia (59%); specificity was >80% for all three conditions. Sensitivity ranged from 86% to 99% for influenza immunization, clinical breast examination, blood cholesterol screening, mammography, Pap test, and blood pressure screening; specificity was <75% for all preventive services. Conclusions: Self-reports are reasonably accurate for certain chronic conditions and for routine screening exams and can provide a useful estimate for broad measures of population prevalence.