The validity of health risk appraisals for coronary heart disease: results from a randomized field trial. BACKGROUND: While health risk appraisals (HRAs) are becoming increasingly popular as tools for health assessment and health education, comparatively little is known about the accuracy of these risk estimates. METHODS: A field trial among 732 randomly selected adults ages 25 to 65 years was conducted to assess the validity of the risk scores produced by four widely used HRAs. RESULTS: Self-reported HRA risk scores for cigarette smoking and relative weight were generally accurate, but correlations between physiological measurements and scores for blood pressure, cholesterol, and physical activity were always lower than .51. Correlations between epidemiologic estimates of the probability of CHD death and HRA total risk scores ranged from .13 to .75; partial correlations adjusting for age, race, and gender ranged from .12 to .47. CONCLUSIONS: The HRAs chosen for the field trial exhibited modest correlations with the CHD mortality risk predicted by the epidemiologic model. Mathematical errors made by respondents completing self-scored instruments and lack of knowledge regarding physiologic status decrease the accuracy of HRA risk estimates. 