Outcome Predictors in Cocaine Dependence Treatment Trials

Abstract

Finding the predictors of outcome in outpatient cocaine dependence treatment trials may be useful for the development of both psychosocial as well as pharmacological treatments for cocaine dependence. Among the most powerful predictors of response to psychosocial treatment are cocaine withdrawal symptom severity and the results of a urine drug screen (UDS) collected at study entry. The present trial seeks to extend these findings by examining outcome predictors in a large number of subjects participating in a series of outpatient cocaine pharmacotherapy trials while selecting three separate criteria to define successful outcome. The ability of several baseline variables were tested to predict treatment outcome in a series of cocaine medication trials that included 402 cocaine-dependent subjects. Predictor variables included results from the baseline Addiction Severity Index (ASI), initial UDS results, and cocaine withdrawal symptom severity at treatment entry, as measured by scores on the Cocaine Selective Severity Assessment (CSSA). Outcome measures included UDS results obtained during the trials and results from the ASI gathered at the end of the trials. Baseline variables that most consistently predicted treatment outcome were the initial UDS results and initial CSSA scores. These findings indicate that baseline UDS results and CSSA scores are powerful predictors of outcome and should be used as stratifying variables in outpatient cocaine medication trials.