Table 2.
Means, standard deviations, and effect sizes for outcomes by group.
| Estimated marginal means |
Percentage changes from pre-ICBT |
Within-group effect sizes from pre-iCBT |
Between-group effect sizes |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Screening | Post-MI | Pre-ICBT | Post-ICBT | 13-week follow-up | 25-week follow-up | To post | To 6-month follow-up | To post | To 25-week follow-up | At post | At 25-week follow-up | |
| Primary outcomes | ||||||||||||
| CQ | ||||||||||||
| MI + iCBT | 25.44 (3.95) | 25.62 (3.64) | – | – | – | – | −1 [−3/1] | – | −0.05 [−0.1/0] | – | −0.06 [0/0.1] | – |
| iCBT only | 25.59 (3.72) | 25.82 (3.74) | – | – | – | – | −1 [−3/1] | – | −0.06 [−0.1/0] | – | ||
| GAD-7 | ||||||||||||
| MI + iCBT | – | – | 11.74 (5.12) | 6.26 (4.78) | 6.25 (4.57) | 6.42 (4.74) | 47 [38/55] | 45 [38/53] | 1.11 [1/1.2] | 1.08 [1/1.2] | −0.01 [−0.1/0.1] | −0.21 [−0.3/0.1] |
| iCBT only | – | – | 11.17 (5.22) | 6.22 (5.05) | 5.81 (4.66) | 5.44 (4.43) | 44 [37/51] | 51 [42/61] | 0.96 [0.9/1] | 1.18 [1.1/1.3] | ||
| PHQ-9 | ||||||||||||
| MI + iCBT | – | – | 12.10 (5.83) | 6.61 (5.21) | 7.28 (5.14) | 7.60 (5.26) | 45 [37/54] | 37 [29/46] | 0.99 [0.9/1.1] | 0.81 [0.7/0.9] | −0.05 [−0.1/0] | −0.20 [−0.3/0.1] |
| ICBT only | – | – | 11.56 (5.70) | 6.33 (5.19) | 6.35 (5.20) | 6.56 (5.20) | 45 [35/56] | 43 [30/56] | 0.96 [0.9/1] | 0.92 [0.8/1] | ||
| Secondary outcomes | ||||||||||||
| Motivation questions | ||||||||||||
| MI + iCBT | 15.81 (2.27) | 16.19 (2.24) | – | – | – | – | −3 [−5/−1] | – | −0.17[−0.3/−0.1] | – | 0.02 [−0.1/0.1] | – |
| iCBT only | 16.13 (2.23) | 16.24 (2.25) | – | – | – | – | −1 [−3/1] | – | −0.05 [−0.1/0] | – | ||
| K10 | ||||||||||||
| MI + iCBT | – | – | 28.06 (7.66) | 21.91 (7.84) | 21.33 (7.14) | 22.12 (7.55) | 22 [17/27] | 21 [17/26] | 0.79 [0.7/0.9] | 0.78 [0.7/0.9] | −0.07 [−0.2/0] | −0.13 [−0.2/0] |
| iCBT only | – | – | 27.37 (7.89) | 21.36 (7.95) | 20.64 (7.55) | 21.13 (7.91) | 22 [16/28] | 23 [15/31] | 0.76 [0.7/0.8] | 0.79 [0.7/0.9] | ||
| SDS | ||||||||||||
| MI + iCBT | – | – | 17.60 (8.02) | 12.01 (8.07) | 11.00 (8.00) | 11.41 (8.34) | 32 [22/41] | 35 [26/44] | 0.69 [0.6/0.8] | 0.76 [0.7/0.8] | −0.09 [−0.2/0] | −0.24 [−0.3/−0.2] |
| iCBT only | – | – | 16.57 (8.67) | 11.27 (8.38) | 9.46 (7.70) | 9.47 (7.99) | 32 [23/41] | 43 [23/62] | 0.62 [0.5/0.7] | 0.85 [0.8/0.9] | ||
Note. MI = motivational interviewing; iCBT = Internet-delivered cognitive behaviour therapy; CQ = Change Questionnaire; GAD-7 = Generalized Anxiety Disorder – 7 items; PHQ-9 = Patient Health Questionnaire – 9 items; K10 = Kessler 10-Item Scale; SDS = Sheehan Disability Scale.