ASSESSING SUBSTANCE USE IN MULTIPROBLEM PATIENTS - RELIABILITY AND VALIDITY OF THE ADDICTION SEVERITY INDEX IN A MENTAL-HOSPITAL POPULATION

The Addiction Severity Index (ASI) is the most widely used measure of substance use in the held. Its reputation has been supported by reliab ility and validity studies. Despite its success, the psychometric prop erties of the ASI have not been examined in mental hospital population s. Our intent was to replicate prior studies and expand upon the valid ity of the ASI in a sample of 100 public psychiatric patients selected for a larger study. Findings revealed that a) reliability was accepta ble, but there was only moderate agreement on the psychiatric scale se verity score; b) the relationship between extent of rater training and reliability requires further study; c) despite some overlap, the scal es were largely independent of each other; d) modification of the empl oyment scale was necessary because of low correlations between the com posite and severity score; e) raters are more responsive to client sub jective ratings in psychiatric settings; f) ASI drug and alcohol scale s correlate well with other substance use instruments and with DSM-III -R diagnoses; and g) the ASI can identify meaningful types of patient problems through cluster analysis. These findings, on the whole, suppo rt the use of the ASI drug and alcohol scales in public psychiatric ho spitals.