New data from the Addiction Severity Index. Reliability and validity in three centers.

The Addiction Severity Index (ASI) is a clinical/research instrument which has been in wide use during the past 6 years to assess the treatment problems found in alcohol- and drug-abusing patients. In a study of male veterans, a preliminary evaluation of the ASI has indicated reliability and validity. The present report presents an expanded examination of these issues; 181 subjects from three treatment centers were studied. Results of concurrent reliability studies indicate that trained technicians can estimate the severity of patients' treatment problems with an average concordance of .89. Test-retest studies show that the information obtained from the ASI is consistent over a 3-day interval, even with different interviewers. Comparisons of the ASI severity ratings and composite measures with a battery of previously validated tests indicate evidence of concurrent and discriminant validity. The reliability and validity results were consistent across subgroups of patients categorized by age, race, sex, primary drug problem, and treatment center. The authors discuss the strengths and limitations of the instrument based upon 5 years of use. The overall conclusion is that the ASI is a reliable and valid instrument that has a wide range of clinical and research applications, and that it may offer advantages in the examination of important issues such as the prediction of treatment outcome, the comparison of different forms of treatment, and the "matching" of patients to treatments.