The reliability and validity of the self-reported drinking measures in the Army's Health Risk Appraisal survey

Background: The reliability and validity of self-reported drinking behaviors from the Army Health Risk Appraisal (HRA) survey are unknown. Methods: We compared demographics and health experiences of those who completed the HRA with those who did not (1991-1998). We also evaluated the reliability and validity of eight HRA alcohol-related items, including the CAGE, weekly drinking quantity, and drinking and driving measures. We used Cohen's kappa and Pearson's r to assess reliability and convergent validity. To assess criterion (predictive) validity, we used proportional hazards and logistical regression models predicting alcohol-related hospitalizations and alcohol-related separations from the Army, respectively. Results: A total of 404,966 soldiers completed an HRA. No particular demographic group seems to be over- or underrepresented. Although few respondents skipped alcohol items, those who did tended to be older and of minority race, The alcohol items demonstrate a reasonable degree of reliability, with Cronbach's alpha=0.69 and test-retest reliability associations in the 0.75-0.80 range for most items over 2- to 30-day interims between surveys. The alcohol measures showed good criterion-related validity: those consuming more than 21 drinks per week were at 6 times the risk for subsequent alcohol-related hospitalization, versus those who abstained from drinking (hazard ratio, 6.36; 95% confidence interval=5.79, 6.99). Those who said their friends worried about their drinking were almost 5 times more likely to be discharged due to alcoholism (risk ratio, 4.9; 95% confidence interval=4.00, 6.04) and 6 times more likely to experience an alcohol-related hospitalization (hazard ratio, 6.24; 95% confidence interval=5.74, 6.77). Conclusions: The Army's HRA alcohol items seem to elicit reliable and valid responses. Because HRAs contain identifiers, alcohol use can be linked with subsequent health and occupational outcomes, making the HRA a useful epidemiological research tool. Associations between perceived peer opinions of drinking and subsequent problems deserve further exploration.