Table 6. Change-score correlation matrix for key variables at T2. Variable 1 2 3 4 5 1. Δ cognitive anxiety (T2 - T0) -- 2. Δ somatic anxiety (T2 - T0) .78** -- 3. Δ self-efficacy (T2 - T0) -.71** -.66** -- 4. Δ mindfulness (FFMQ) (T2 - T0) -.65** -.61** .59** -- 5. Intervention engagement (minutes; IG only) -.52** -.48** .58** .67** -- Variables 1-4 are change scores from baseline to post-intervention (T2 - T0) and are based on the full intention-to-treat sample (N=70). Variable 5 uses intervention-group app-use data only (n = 35); correlations involving engagement should therefore be interpreted within the intervention group. ** p < .01.