Reliability of the health hazard appraisal

As part of a controlled clinical trial of Health Hazard Appraisal's (HHA) efficacy in stimulating risk reduction, the reliability of the HHA questionnaire was evaluated. Of 203 subjects, only 30 (15%) had no contradictions when comparing the responses of the follow-up with baseline questionnaire. Overall, there was an average of 1.6 contradictions per subject. Failure to control for reliability may account for apparent reduction of risk reported in previous studies of HHA.