A two-rate hypothesis for patterns of retention in psychosocial treatments of cocaine dependence: findings from a study of African-American men and a review of the published data.

In this article, we examine patterns of retention in psychosocial treatment programs for cocaine dependence. We present new data from a comparison trial of Drug Counseling and Supportive-Expressive Psychotherapy and review published data from all studies utilizing psychosocial interventions alone. We compared Drug Counseling and Psychotherapy on rates of pretreatment and during-treatment attrition in a sample of 294 African-American men seeking treatment for cocaine dependence (mean age, 37.6). Survival analyses were utilized to identify significant differences in during-treatment attrition between the two treatments and to identify significant changes in the rate of attrition during the course of each treatment. We then compared the patterns of retention in this study with those from other available published reports of psychosocial treatments for cocaine abuse. The weekly during-treatment attrition rate was not constant in either treatment condition, and the change in rate of attrition occurred at week six for both Drug Counseling and Psychotherapy. Comparison with other studies suggested that the during-treatment pattern of attrition among most psychosocial treatments for cocaine abuse is typified by two rates, with the rate of subject attrition early in treatment being greater than the rate of later attrition and also exhibiting greater variance. Future studies of treatment retention should identify significant shifts in the rate of during-treatment attrition, examine if the pattern of attrition is typified by two rates, and, if so, determine where the shift occurs. Future studies should also assess if changes in the rate of during-treatment attrition signal the timeframes within which strategies that enhance retention can be implemented in the treatment program.