RELIABILITY AND CHANGES IN VALIDITY OF SELF-REPORTED CARDIOVASCULAR-DISEASE RISK-FACTORS USING DUAL RESPONSE - THE BEHAVIORAL RISK FACTOR SURVEY

The authors previously studied the validity of self-reported cardiovas cular disease (CVD) risk factors assessed by telephone surveys, and fo und the validity low, especially for self-reported hypertension and hy percholesterolemia. One way to improve validity is to combine repeated measurements (dual response) into a single measure. The authors explo red this and the reliability of self-reported CVD data collected by th e Behavioral Risk Factor Survey in three New York counties from Januar y 1989 to May 1990. Nine hundred and eleven subjects were interviewed by telephone to collect CVD risk factor and health behavior informatio n. Interviewees were offered physical examination and laboratory testi ng to verify self-reported CVD risk factors; 628 participated. Subject s were also reinterviewed to assess the test-retest reliability of the survey, and to study how validity of self-reported CVD data changes b y dual response. Reliability coefficients for CVD risk factors, preven tive health practices, and knowledge of risk factor levels ranged from 0.42 to 0.99. Minimal improvement in sensitivity of self-reported ris k factors was found using dual response, and it did not improve specif icity. Also, for prevalence of risk factors, dual response minimally i mproved self-reported rates compared to objective estimates. Combining self-reported measurements causes minimal changes in the validity of these variables. Physiological assessment for hypertension and hyperch olesterolemia, or correction for misclassification, is needed for vali d individual measurement and for community prevalence estimates from t elephone surveys. Self-reported cigarette smoking, obesity, and diabet es mellitus have better validity, but physiological assessment or corr ection for misclassification may supplement these self-reported risk f actors.