Project MATCH secondary a priori hypotheses. Project MATCH Research Group

Abstract

Aims: (1) To assess the benefits of matching alcohol dependent clients to three treatments, based upon a priori hypotheses involving 11 client attributes; (2) to discuss the implications of these findings and of matching hypotheses previously reported from Project MATCH.

Setting and participants: (1) Clients receiving outpatient therapy (N = 952; 72% male); (2) clients receiving aftercare therapy following inpatient or day hospital treatment (N = 774; 80% male).

Intervention: Clients were randomly assigned to one of three 12-week, manual-guided, individual treatments: Cognitive Behavioral Coping Skills Therapy (CBT), Motivational Enhancement Therapy (MET) or Twelve-Step Facilitation Therapy (TSF).

Design: Two parallel but independent randomized clinical trials were conducted, one with outpatients, one with aftercare clients. Participants were monitored over 15 months including a 1-year post-treatment period. Individual differences in response to treatment were modeled as a latent growth process and evaluated for 17 contrasts specified a priori. Outcome measures were percentage of days abstinent and drinks per drinking day.

Findings: Two a priori contrasts demonstrated significant post-treatment attribute by treatment interactions: (1) outpatients high in anger and treated in MET had better post-treatment drinking than in CBT; (2) aftercare clients high in alcohol dependence had better post-treatment outcomes in TSF; low dependence clients did better in CBT. Other matching effects varied over time, while still other interactions were opposite that predicted.

Conclusions: (1) Anger and dependence should be considered when assigning clients to these three treatments; (2) considered together with the results of the primary hypotheses, matching effects contrasting these psychotherapies are not robust. Possible explanations include: (a) among the client variables and treatments tested, matching may not be an important factor in determining client outcomes; (b) design issues limited the robustness of effects; and (c) a more fully specified theory of matching is necessary to account for the complexity of the results.