High attrition continues to be an important issue for substance abuse treatment providers. This study examined factors contributing to treatment entry and dropout after referral from centralized assessment. Univariate analysis showed that individuals with a shorter wait after assessment were more likely to attend an initial treatment appointment, while those who reported a history of physical or sexual abuse or were on probation were significantly more likely to drop out of treatment early. Multivariate analysis revealed, first, that persons with a comorbid psychiatric diagnosis and those referred to outpatient rather than residential care were less likely to enter treatment; and, second, that persons on probation and with a history of physical or sexual abuse were more likely to be early treatment dropouts. Findings suggest that decisions to seek help and to accept help are distinct, and that program factors play a substantial role in treatment engagement and retention.

Previous research has emphasized the importance of minimizing attrition in longitudinal studies. The authors examined the influence of demographic, clinical, and process factors on attrition from a longitudinal study of 286 substance abusers recruited at a central intake unit. Univariate tests showed that those who completed three, six, and 12 month interviews had higher baseline alcohol and drug use and were more likely to provide three or more contacts when recruited, to be female, to have been married, and to have previously received substance abuse or psychiatric treatment. Multivariate logistic regression revealed that complete data participants (those who completed all three ASI interviews) were nearly three times more likely to have previously received psychiatric treatment and twice as likely to have completed an early engagement interview. In addition, they were twice as likely to be female, and nearly twice as likely to be employed, own a residence, have completed high school, and be married. Procedures that may help decrease study attrition are discussed.