AUDIT-C as a brief screen for alcohol misuse in primary care

Background: The Alcohol Use Disorders Identification Test Consumption (AUDIT-C) questions have been previously validated as a 3-item screen for alcohol misuse and implemented nationwide in Veterans Affairs (VA) outpatient clinics. However, the AUDIT-C's validity and optimal screening threshold(s) in other clinical populations are unknown. Methods: This cross-sectional validation study compared screening questionnaires with standardized interviews in 392 male and 927 female adult outpatients at an academic family practice clinic from 1993 to 1994. The AUDIT-C, full AUDIT, self-reported risky drinking, AUDIT question #3, and an augmented CAGE questionnaire were compared with an interview primary reference standard of alcohol misuse, defined as a Diagnostic and Statistical Manual, 4th ed. alcohol use disorder and/or drinking above recommended limits in the past year. Results: Based on interviews with 92% of eligible patients, 128 (33%) men and 177 (19%) women met the criteria for alcohol misuse. Areas under the receiver operating characteristic curves (AUROCs) for the AUDIT-C were 0.94 (0.91, 0.96) and 0.90 (0.87, 0.93) in men and women, respectively (p=0.04). Based on AUROC curves, the AUDIT-C performed as well as the full AUDIT and significantly better than self-reported risky drinking, AUDIT question #3, or the augmented CAGE questionnaire (p-values <0.001). The AUDIT-C screening thresholds that simultaneously maximized sensitivity and specificity were ≥4 in men (sensitivity 0.86, specificity 0.89) and ≥3 in women (sensitivity 0.73, specificity 0.91). Conclusions: The AUDIT-C was an effective screening test for alcohol misuse in this primary care sample. Optimal screening thresholds for alcohol misuse among men (≥4) and women (≥3) were the same as in previously published VA studies.