Validity of the CAGE questionnaire in an American Indian population

Objective: This study evaluated the performance of the CAGE questionnaire (a set of four questions about alcoholism) in an American Indian population. Method: We analyzed data from a cross-sectional study of 275 individuals (179 women) aged 21 years or older. Alcohol dependence was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Third Edition-Revised (DSM-III-R), based on a detailed psychiatric interview using the Schedule for Affective Disorders and Schizophrenia-Lifetime Version. Accuracy of the CAGE questionnaire was quantified as sensitivity, specificity, likelihood ratios and the area under receiver operating characteristics (ROC) curves, using the DSM-III-R diagnosis as the reference. Results: Of participants interviewed 85% of men and 53% of women had a diagnosis of alcohol dependence by DSM-III-R. A CAGE score of greater than or equal to 2 had a sensitivity and specificity of 68% and 93%, respectively, in men and 62% and 79% in women, for the diagnosis of alcohol dependence. CAGE scores of 0, 1 and greater than or equal to 2 were associated with likelihood ratios of 0.3, 0.3 and 9.5, respectively, in men and 0.4, 0.7 and 1.5 in women. The area under the ROC curve was 81% for men and 75% for women. Conclusions: These findings suggest that the CAGE questionnaire is a valid screening method, in this population, for identifying people likely to have alcohol dependence.