Cluster membership interacts with responses to treatment
Anxiety, anxiety
To test whether subgroup membership interacted with clinical outcomes, we conducted a TIME (baseline, 1 month, 2 months) X GROUP (TAU + MT, TAU) X CLUSTER mixed measures ANOVA on GAD-7 scores. We found a significant TIME X GROUP X CLUSTER interaction (F(3.75, 106.95) = 2.72, p = 0.037, Follow-up GROUP X TIME ANOVAs within each cluster (alpha for the omnibus F divided by 3 for the three post-hoc ANOVAs performed: 0.05/3 = 0.017) revealed a significant GROUP X TIME interaction for cluster 1 (F(1.77, 19.41) = 31.39, p < 0.001, Post-hoc within-subjects comparisons (alpha corrected to 0.008 adjusted for 6 contrasts) were performed within each cluster by comparing GAD7 scores between each assessment timepoint (30 and 60 days post-treatment initiation) and baseline for treatment group participants relative to controls. For clusters 1 and 3, these revealed significant contrasts between anxiety scores at the 30 day assessment timepoint and baseline as well as between the 60 day assessment timepoint and baseline for subjects in MT + TAU vs TAU (Cluster1: p < 0.001 for both contrasts; Cluster 3: p = 0.005 comparing GAD7 scores at 30 day vs baseline for MT + TAU vs TAU, p < 0.001 comparing GAD7 scores for 60 day vs baseline for MT + TAU vs TAU). For cluster 2, no significant differences were revealed by the comparisons between anxiety scores at the 30-day assessment timepoint and baseline (p = 0.065) for treatment relative to the control group, as well as the contrast comparing anxiety scores at the 60-day assessment timepoint and baseline (p = 0.215)To determine whether group mean values in GAD scores significantly differed between clusters at baseline, Finally, the TIME (1 month and 2 months post-treatment initiation) X CLUSTER ANOVA on number of mindfulness program modules completed did not reveal any significant main effect of CLUSTER (F(2, 25) = 0.50, p = 0.611, Table Anxiety (GAD-7 scores) and engagement (number of modules completed) by treatment group and cluster at each assessment timepoint.TAU + MT = treatment as usual + mindfulness training; TAU: treatment as usual; GAD-7: generalized anxiety disorder-7 item scale.**