Comparison of outcomes for clients in randomized versus open trials of treatment for alcohol use disorders

Objective: There has been continuing concern that clients who accept random ization into a controlled trial may not be representative of those in nonco ntrolled trials or ordinary treatment situations. However, it is not possib le to test the impact of randomization through a randomized trial. Two para llel studies conducted at the same treatment facility provided an opportuni ty for a quasi-experimental study to evaluate whether participation in a co ntrolled trial itself affects treatment outcome. Method: Two concomitant sa mples of clients were enrolled during overlapping recruitment periods: one (n = 226) into a randomized clinical trial (RCT) and the other (n = 122) of fered treatment as usual (non-RCT). Both samples were given extensive basel ine and follow-up assessment. Results: Baseline assessment indicated demogr aphic similarity of the two samples, with somewhat higher problem severity in the non-RCT sample, consistent with the RCT selection criteria. Client r etention in treatment was somewhat comparable, and follow-up rates exceeded 90% in both studies. Overall outcomes did not differ for the RCT and non-R CT samples. Conclusions: It appeared that clients enrolled into an RCT did not differ from those receiving ordinary treatment. Retention was similarly high in both studies, clients completed a comparable number of outpatient sessions, and the number of informal treatment sessions attended during the 6 months of follow-up was comparable. There are some aspects of this study that limit the ability to draw firmer conclusions but despite some pretrea tment differences, participation in the RCT did not itself exert an apparen t effect on aggregate treatment outcomes.