Table 3.
Estimated means (standard deviations) for BDI-II and MADRS-S from pre-treatment to the 24-month assessment, effect sizes within and between groups.
| Group | Pre [M (SD)] |
Post [M (SD)] |
WG d | BG d | 6-m [M (SD)] |
WG d | BG d | 12-m [M (SD)] |
WG d | BG d | 24-m [M (SD)] |
WG d | BG d | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BDI-II | ICBT | 29.5 (7.6) | 18.5 (11.8) | 1.11 | 0.23 | 14.7 (10.4) | 1.62 | 0.18 | 15.3 (11.8) | 1.43 | 0.08 | 13.5 (7.5) | 2.11 | 0.00 |
| CONT | 27.0 (7.5) | 21.2 (11.7) | 0.59 | 16.6 (11.0) | 1.10 | 16.3 (13.7) | 0.97 | 13.5 (15.4) | 1.11 | |||||
| MADRS-S | ICBT | 23.2 (4.2) | 14.5 (8.3) | 1.32 | 0.23 | 12.3 (7.6) | 1.78 | 0.27 | 12.9 (9.7) | 1.38 | 0.13 | 11.9 (10.6) | 1.40 | 0.03 |
| CONT | 22.9 (4.1) | 16.5 (8.9) | 0.92 | 14.4 (8.2) | 1.31 | 14.3 (11.7) | 0.98 | 11.6 (12.0) | 1.26 | |||||
| Q9 MADRS-S | ICBT | 2.1 (1.0) | 1.4 (1.1) | 0.67 | 0.09 | 1.1 (1.1) | 0.95 | 0.09 | 1.2 (1.3) | 0.78 | 0.07 | 1.0 (1.7) | 0.81 | 0.06 |
| CONT | 2.2 (1.0) | 1.5 (1.2) | 0.63 | 1.2 (1.2) | 0.91 | 1.3 (1.6) | 0.67 | 1.1 (1.4) | 0.92 |
Note. BDI-II = Beck Depression Inventory – Second Edition, BG = between-group, ICBT = internet-based cognitive behavior therapy, CONT = control group, d = Cohen's d, M = mean, MADRS-S = Montgomery-Åsberg Depression Rating Scale – self-rated version, SD = standard deviation, WG = within-group. All the within-group effect sizes were calculated based on the pre-treatment scores.