Table 3.
Estimated mean scores of primary and secondary outcomes, effect sizes and treatment group comparisons
| SCREEN m (SE) | PRE m (SE) | MID m (SE) | POST m (SE) | Effect sizes, g [CI] within-group | Effect size, g [CI] between-group | G*T p | |
| Primary outcome | |||||||
| WSAS | 0.69 [0.23, 1.15] | Wχ2= 26.23 | |||||
| ICBT | 25.71 (1.06) | 22.92 (1.06) | 22.13 (1.09) | 21.48 (1.05) | 0.64 [0.18, 1.10] | p = 0.001 | |
| CONTROL | 25.84 (1.05) | 24.84 (1.05) | 26.04 (1.06) | 26.04 (1.07) | –0.03 [–0.47, 0.40] | ||
| p | p = 0.934 | p = 0.213 | p = 0.010 | p = 0.002 | |||
| Secondary outcomes | |||||||
| HADS-A | – | – | 0.51 [0.06, 0.96] | Wχ2= 12.19 | |||
| ICBT | 7.79 (0.59) | 6.87 (0.61) | 0.25 [–0.21, 0.70] | p = 0.007 | |||
| CONTROL | 7.59 (0.58) | 8.79 (0.59) | –0.33 [–0.77, 0.12] | ||||
| HADS-D | – | – | 0.68 [0.22, 1.14] | Wχ2= 11.20 | |||
| ICBT | 7.34 (0.54) | 6.36 (0.53) | 0.29 [–0.16, 0.75] | p = 0.011 | |||
| CONTROL | 8.08 (0.53) | 8.62 (0.53) | –0.16 [–0.61, 0.28] | ||||
| ISI | – | – | 0.38 [–0.07, 0.83] | Wχ2= 18.92 | |||
| ICBT | 13.95 (0.95) | 10.87 (0.97) | 0.52 [0.06, 0.75] | p = <0.001 | |||
| CONTROL | 13.51 (0.93) | 13.15 (0.94) | 0.06 [–0.38, 0.50] | ||||
| PDQ-8 | – | – | 0.65 [0.19, 1.11] | Wχ2= 15.55 | |||
| ICBT | 54.14 (1.79) | 49.10 (1.83) | 0.48 [–0.01, 0.90] | p = 0.001 | |||
| CONTROL | 54.87 (1.77) | 56.45 (1.78) | –0.14 [–0.59, 0.30] | ||||
| WHODAS-2 | – | 0.71 [0.25, 1.17] | Wχ2= 17.22 | ||||
| ICBT | 21.16 (1.07) | 20.24 (1.07) | 19.21 (1.09) | 0.29 [–0.16, 0.74] | p = 0.004 | ||
| CONTROL | 22.10 (1.06) | 22.23 (1.06) | 23.97 (1.06) | –0.28 [–0.73, 0.17] | |||
| BBQa | – | – | 0.73 [0.26, 1.19] | Wχ2= 13.03 | |||
| ICBT | 50.00 (3.04) | 56.18 (3.15) | 0.32 [–0.13, 0.77] | p = 0.005 | |||
| CONTROL | 41.77 (3.00) | 42.12 (3.03) | 0.02 [–0.43, 0.46] | ||||
| SSES6a | – | – | 0.23 [–0.21, 0.68] | Wχ2= 1.29 | |||
| ICBT | 26.11 (1.72) | 26.31 (1.81) | 0.02 [–0.43, 0.47] | p = 0.732 | |||
| CONTROL | 24.97 (1.69) | 23.72 (1.71) | –0.12 [–0.56, 0.33] |
Bold values are statistically significant p < 0.05; aReversed scale (higher is better); WSAS, Work and Social Adjustment Scale; ICBT, treatment group; CONTROL, waitlist group; HADS-A, Hospital Anxiety and Depression Scale-Anxiety; HADS-D, Hospital Anxiety and Depression Scale-Depression; ISI, Insomnia Severity Index; PDQ-8, Parkinson’s Disease Questionnaire-8; WHODAS-2, World Health Organization Disability Assessment Schedule 2 - 12-item; BBQ, Brunnsviken Brief Quality of life scale; SSES6, Stanford Self-Efficacy for Managing Chronic Disease.