Table 2. Observed means and standard deviations for clinical outcome variables at baseline, post-treatment and one-year follow-up within each group, within-group effects and between-group effects based on estimated means.
| Blended CBT | Within-group effect size a | Face-to-face CBT | Within-group effect size a | Between-group comparison b | Between-group effect size c | |||
|---|---|---|---|---|---|---|---|---|
| Measure | n | Mean (SD) | Cohen’s d (95% CI) | n | Mean (SD) | Cohen’s d (95% CI) | t (p-value) | Cohen’s d (95% CI) |
| Primary outcome | ||||||||
| Anxiety (BAI) | ||||||||
| Baseline | 51 | 27.90 (12.02) | 62 | 27.15 (11.67) | ||||
| Post-treatment | 34 | 17.18 (10.28) | 0.73 (0.49, 0.97) | 43 | 18.93 (11.55) | 0.55 (0.34, 0.75) | −0.715 (0.477) | 0.15 (−0.30, 0.60) |
| 1-year follow-up | 34 | 19.97 (13.12) | 0.50 (0.25, 0.74) | 40 | 14.28 (9.06) | 1.00 (0.74, 1.26) | 1.702 (0.093) | −0.38 (−0.84, 0.09) |
| Secondary outcomes | ||||||||
| Depression (BDI-II) | ||||||||
| Baseline | 52 | 23.98 (12.17) | 62 | 24.00 (10.26) | ||||
| Post-treatment | 34 | 16.50 (11.63) | 0.53 (0.30, 0.76) | 42 | 18.69 (10.76) | 0.42 (0.21, 0.62) | −0.801 (0.425) | 0.16 (−0.30, 0.61) |
| 1-year follow-up | 32 | 15.69 (11.13) | 0.72 (0.45, 0.98) | 39 | 14.69 (9.44) | 0.59 (0.36, 0.82) | 0.203 (0.840) | −0.04 (−0.51, 0.43) |
| General psychopathology (BSI) | ||||||||
| Baseline | 52 | 1.43 (0.72) | 62 | 1.36 (0.67) | ||||
| Post-treatment | 34 | 0.97 (0.63) | 0.67 (0.44, 0.91) | 42 | 0.95 (0.66) | 0.50 (0.29, 0.70) | −0.130 (0.897) | 0.02 (−0.43, 0.48) |
| 1-year follow-up | 32 | 1.00 (0.66) | 0.63 (0.37, 0.89) | 39 | 0.75 (0.61) | 0.98 (0.72, 1.24) | 1.339 (0.185) | −0.27 (−0.74, 0.20) |
| Mastery (Mastery Scale) | ||||||||
| Baseline | 52 | 14.90 (4.45) | 62 | 14.26 (4.39) | ||||
| Post-treatment | 34 | 16.12 (4.20) | −0.26 (−0.48, −0.05) | 42 | 16.05 (4.70) | −0.42 (−0.6, −0.22) | −0.290 (0.773) | 0.05 (−0.40, 0.51) |
| 1-year follow-up | 32 | 15.56 (4.96) | −0.13 (−0.37, 0.10) | 39 | 17.38 (4.78) | −0.63 (−0.86, −0.40) | −2.329 (0.023) | 0.48 (0.01, 0.96) |
| Work and social adjustment (WSAS) | ||||||||
| Baseline | 52 | 23.00 (10.22) | 62 | 23.90 (9.11) | ||||
| Post-treatment | 34 | 17.47 (9.61) | 0.65 (0.41, 0.88) | 42 | 18.95 (10.02) | 0.35 (0.16, 0.55) | −0.751 (0.455) | 0.15 (−0.31, 0.60) |
| 1-year follow-up | 32 | 16.34 (11.21) | 0.66 (0.40, 0.92) | 39 | 17.97 (10.77) | 0.48 (0.26, 0.71) | −0.775 (0.441) | 0.17 (−0.03, 0.64) |
| Quality of life (EQ-5D utility scores) | ||||||||
| Baseline | 52 | 0.55 (0.28) | 62 | 0.53 (0.26) | ||||
| Post-treatment | 34 | 0.69 (0.20) | −0.47 (−0.69, −0.25) | 43 | 0.61 (0.25) | −0.28 (−0.47, −0.08) | 1.235 (0.220) | −0.24 (−0.69, 0.21) |
| 1-year follow-up | 34 | 0.69 (0.27) | −0.40 (−0.64, −0.16) | 40 | 0.71 (0.25) | −0.60 (−0.83, −0.37) | −0.498 (0.620) | 0.11 (−0.35, 0.56) |
* Note, Bonferroni-Holm corrected significance level is p = 0.01.
Abbreviations: bCBT: blended cognitive-behavioural therapy; ftfCBT: face-to-face cognitive-behavioural therapy; BAI: Beck Anxiety Inventory; BDI-II: Beck Depression Inventory-II; BSI: Brief Symptom Inventory; WSAS: Work and Social Adjustment Scale; EQ-5D-5L: EuroQol.
a Within-group effect sizes were calculated based on estimated means from the linear mixed model using raw differences.
b Between-group comparisons were based on estimated means from the linear mixed model with baseline adjustment.
c Between-group effect sizes were calculated based on estimated means from the linear mixed model with baseline adjustment.