Psychometric properties of the Drug Use Disorders Identification Test (DUDIT) with substance abusers in outpatient and residential treatment.

The psychometric properties of the Drug Use Disorders Identification Test (DUDIT), an 11-item self-report questionnaire developed to screen individuals for drug problems, are evaluated. The measure, developed in Sweden and evaluated there with individuals with severe drug problems, has not been evaluated with less severe substance abusers or with clinical populations in the United States. Participants included 35 drug abusers in an outpatient substance abuse treatment program, 79 drug abusers in a residential substance abuse treatment program, and 39 alcohol abusers from both treatment settings who did not report a drug abuse problem. The DUDIT was found to be a psychometrically sound drug abuse screening measure with high convergent validity (r=.85) when compared with the Drug Abuse Screening Test (DAST-10), and to have a Cronbach's alpha of .94. In addition, a single component accounted for 64.91% of total variance, and the DUDIT had sensitivity and specificity scores of .90 and .85, respectively, when using the optimal cut-off score of 8. Additionally, the DUDIT showed good discriminant validity as it significantly differentiated drug from alcohol abusers. These findings support the DUDIT as a reliable and valid drug abuse screening instrument that measures a unidimensional construct. Further research is warranted with additional clinical populations.