Generic versus disease-specific health status measures. An example using coronary artery disease and congestive heart failure patients

The objectives of this study were to evaluate and compare the psychometric properties of a generic health status measure, the Medical Outcomes Study SF-36, and a disease-specific health status measure, a modified version of the Chronic Heart Failure Questionnaire (CHQ), among outpatients known to have coronary artery disease (CAD) and/or congestive heart failure (CHF). A cross-sectional analysis of baseline data obtained from 670 outpatients participating in a randomized controlled clinical trial in the general medicine clinics of a major academic medical center was performed. The SF-36 was more comprehensive in its coverage of different health status domains. In contrast, the CHQ had fewer problems with floor and ceiling effects, was more internally consistent, had better dimensional reproducibility, and exhibited less factorial complexity. Although both instruments are appropriate for use among outpatients known to have CAD and/or CHF, the CHQ has significantly better psychometric properties than does the SF-36.