Abstract
Aims To examine the reliability and validity of the widely used Addiction Severity Index (ASI). Material Thirty-seven studies of the psychometric performance of the ASI. Findings The inter-rater and test–retest reliabilities of the severity ratings and composites scores vary from excellent to unsatisfactory. High internal consistencies have been reported regularly for only three of the seven composite scores (medical status, alcohol use, psychiatric status). The remaining four composite scores (employment status, drug use, legal status, family/social relations) have low consistencies in at least four different studies. Coefficients of criterion validity are often low. Conclusions There is a discrepancy between the psychometric performance of the ASI and its purported clinical, administrative and research uses.