A multi-service practice research network study of large group psychoeducational cognitive behavioural therapy

Background This was a multi-service evaluation of the clinical and organisational effectiveness of large group psychoeducational CBT delivered within a stepped care model. Method Clinical outcomes for 4451 participants in 163 psychoeducational groups delivered across 5 services were analysed by calculating pre-post treatment anxiety (GAD-7) effect sizes (Cohen's d). Overall and between-service effects were compared to published efficacy benchmarks. Multilevel modelling was used to examine if variability in clinical outcomes was explained by differences in service, group and patient-level (case-mix) variables. Results The pooled GAD-7 (pre-post) effect size for all services was d = 0.70, which was consistent with efficacy benchmarks for guided self-help interventions (d = 0.69). One service had significantly smaller effects (d = 0.48), which was explained by differences in group treatment length and case-mix. Variability between groups (i.e., group effects) explained up to 3.6% of variance in treatment outcomes. Conclusions Large group psychoeducational CBT is clinically effective, organisationally efficient and consistent with a stepped care approach to service design. Clinical outcome differences between services were explained by group and patient variables.