Table 2.
Estimated marginal means (standard deviations) for primary and secondary outcome measures, within-group effect sizes, and between-group effect sizes.
| Measure | Baseline Meana (SD) |
Mid Meanb (SD) |
Post Meanc (SD) |
Within t (df) Baseline, Post |
Within ESd (95% CI) Baseline, Post |
Between ESe (95% CI) Post |
F (time by group) |
| PHQ-9f iCBTg |
15.95 (5.25) | 10.69 (4.98) | 7.72 (4.96) | 10.55 (159.32) | 1.90 (1.34-2.45) | 0.78 (0.30-1.25) |
F3,122.84=10.41, P<.001 |
| PHQ-9 TAUh |
14.29 (5.25) | 11.88 (5.15) | 11.70 (5.15) | 3.91 (152.40) | 0.53 (0.12-0.94) | - | - |
| HbA1cfi iCBT |
7.87 (1.79) or 63 mmol/mol |
- | 7.98 (1.73) or 64 mmol/mol |
−0.48 (75.48) | −0.03 (−0.52 to 0.45) | −0.14 (−0.62 to 0.34), nsj |
F1,74.23=0.11 P=.75, ns |
| HbA1c TAU |
7.72 (1.82) or 61 mmol/mol |
- | 7.73 (1.76) or 61 mmol/mol |
−0.05 (72.47) | -0.01 (−0.43 to 0.41) | - | - |
| PAIDk iCBT |
45.73 (21.45) | 38.65 (19.74) | 28.00 (19.65) | 7.74 (155.89) | 1.18 (0.68-1.69) | 0.80 (0.32-1.27) |
F3,87.03=10.32, P=.01 |
| PAID TAU |
46.87 (21.28) | 44.43 (20.82) | 41.55 (20.82) | 2.83 (152.09) | 0.24 (−0.16 to 0.65), ns | - | - |
| K-10l iCBT |
30.73 (6.47) | 23.46 (6.17) | 19.54 (6.12) | 12.03 (157.66) | 2.59 (1.96-3.22) | 1.06 (0.57-1.54) |
F2,155.20=21.86, P<.001 |
| K-10 TAU |
29.39 (6.51) | 26.10 (6.38) | 26.28 (6.44) | 3.99 (151.50) | 0.41 (0.00-0.81) | - | - |
| SF-12 MCSm iCBT | 30.22 (10.12) | - | 39.26 (9.80) | −5.38 (84.04) | −0.85 (−1.34 to −0.34) | −0.66 (−1.12 to −0.19) |
F1,87.40=9.07, P=.01 |
| SF-12 MCS TAU |
29.79 (10.01) | - | 32.70 (9.97) | −2.09 (77.55) | −0.27 (−0.68 to 0.13), ns | - | - |
| SF-12 PCSn iCBT |
40.15 (12.49) | - | 41.1 (11.64) | −0.59 (80.95) | −0.08 (−0.55 to 0.38), ns | 0.15 (−0.30 to 0.60), ns |
F1,78.92=0.27, P=.60, ns |
| SF-12 PCS TAU |
42.94 (11.27) | - | 42.8 (11.12) | 0.11 (75.97) | −0.01 (−0.39 to 0.41), ns | - | |
| GAD-7o iCBT |
10.73 (4.80) | - | 4.60 (4.62) | 7.21 (84.11) | 1.38 (0.86-1.90) | 0.72 (0.25-1.19) |
F1,81.40=13.18, P<.001 |
| GAD-7 TAU |
10.11 (4.76) | - | 8.02 (4.75) | 2.97 (77.74) | 0.42 (0.02-0.83) | - | |
| PHQ-15p iCBT |
11.90 (4.61) | - | 8.65 (4.57) | 3.23 (90.24) | 0.63 (0.15-1.11) | 0.21 (−0.24 to 0.67), ns |
F1,86.59=1.84, P=.18, ns |
| PHQ-15 TAU |
11.10 (4.55) | - | 9.65 (4.68) | 1.68 (81.88) | 0.33 (−0.08 to 0.73), ns |
aBaseline: iCBT: n=41, TAU: n=49.
bMid-treatment: iCBT: n=32, TAU: n=46.
cPosttreatment: iCBT: n=31, TAU: n=46.
dWithin-group ES=Cohen d.
eBetween-group ES=Hedges g with Hedges pooled SD.
fPHQ-9: patient health questionnaire-9.
giCBT: Internet-based cognitive behavioral therapy group.
hTAU: treatment as usual group.
iHbA1c: haemoglobin A1c.
jns: not significant, P>.05.
kPAID: problem areas in diabetes scale.
lK-10: Kessler 10-item psychological distress scale.
mSF-12 MCS: short form 12-item mental health subscale.
nSF-12 PCS: short form 12-item physical health subscale.
oGAD-7: generalized anxiety disorder 7-item scale.
pPHQ-15: patient health questionnaire 15-item somatization scale.