Multidimensionality and prediction of treatment outcome in opioid addicts: 2.5-year follow-up

Abstract

Treatment outcome for drug abusers may be almost entirely dependent on drug abstinence (unidimensional view) or may involve a complex of several relatively independent dimensions. In a 2.5-year follow-up of 150 opiate addicts, we found that their medical, social, psychological, legal, and employment problems, as assessed by the Addiction Severity Index (ASI), improved substantially. Clinician ratings demonstrated more improvement than self-report composites of medical, employment, and family problems. Using factor analysis, the seven outcome areas covered by the ASI formed two factors that accounted for about 50% of the variance at both intake assessment and follow-up. The first factor included strong loadings from the employment, medical, psychological, family, and alcohol problem scales, while the second factor included the drug and legal problem scales primarily. Drug abstinence was correlated with better drug abuse and legal outcome at the 2.5-year follow-up, and abstainers showed more improvement than continued abusers. However, in most non-drug abuse areas the differences between abstainers and abusers were relatively small. Follow-up outcomes were only weakly predicted by the intake clinician ratings of problems, and the intake ratings did not have high specificity in predicting corresponding outcome areas. Thus, a unidimensional view focusing on abstinence described an important part of drug abuse treatment outcome, but a psychosocial factor, that did not include drug abuse, accounted for a large part of outcome variance.