摘要:AIMS To explore the effects of client and therapist characteristics along with percentage of days abstinent before admission on retention and effectiveness of outpatient substance abuse treatment. DESIGN The study was implemented with naturalistic principles and prospective design. The clients (N = 327) and the therapists (N = 33) were recruited from Finnish outpatient treatment units (N = 7). Results The client's low readiness to change, the therapist's low directiveness and low empathy predicted short duration of treatment. Client's past substance use frequency was likewise a significant predictor of retention in treatment; clients with low percentage of days abstinent at baseline dropped out much more easily. The client's high anger and low percentage of days abstinent at baseline was found to predict low percentage of days abstinent at follow-up. Greater satisfaction with support from therapist was predicted by client's high readiness to change and lower substance use frequency at baseline. Conclusions Retention in treatment was predicted by both client's and therapist's characteristics, while effectiveness in outpatient substance abuse treatment was more dependent on client's characteristics and earlier substance use.