Table 3.
Results of main analyses (multilevel and traditional meta-analyses) for primary outcomes comparing transdiagnostic psychosocial interventions with control conditions.
| Confidence interval | Prediction interval | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Analysis | n | k | M(SMD) | 95%l | 95%u | 95%l | 95%u | p | Q | df | p(Q) | I2 (I2S, I2O) |
| Children and adolescents | ||||||||||||
| Mental symptoms (ML) | 12 | 22 | 0.08 | –0.21 | 0.36 | –0.67 | 0.83 | .562 | 75.31 | 21 | <.001 | 69.9 (49.5, 20.4) |
| Psychological distress (T) | 8 | 8 | –0.01 | –0.21 | 0.20 | –0.39 | 0.38 | .951 | 10.18 | 7 | .179 | 33.7 |
| Depressive symptoms (T) | 6 | 6 | –0.22 | –0.65 | 0.22 | –1.28 | 0.85 | .332 | 33.19 | 5 | <.001 | 84.7 |
| Anxiety symptoms (T) | 2 | 2 | 0.09 | –0.53 | 0.72 | –0.90 | 1.09 | .767 | 4.31 | 1 | .038 | 76.8 |
| PTSD symptoms (T) | 6 | 6 | 0.19 | –0.15 | 0.52 | –0.55 | 0.92 | .271 | 14.62 | 5 | .012 | 67.4 |
| Positive MH (T) | 5 | 5 | –0.03 | –0.26 | 0.20 | –0.42 | 0.36 | .823 | 5.93 | 4 | .205 | 39.1 |
| Adults | ||||||||||||
| Mental symptoms (ML) | 26 | 58 | 0.33 | –0.03 | 0.69 | –1.45 | 2.10 | .072 | 441.38 | 57 | <.001 | 96.1 (95.3, 0.8) |
| Psychological distress (T) | 16 | 16 | 0.44 | 0.22 | 0.67 | –0.36 | 1.25 | <.001 | 67.35 | 15 | <.001 | 82.0 |
| Depressive symptoms (T) | 14 | 14 | 0.22 | –0.32 | 0.76 | –1.82 | 2.26 | .430 | 136.07 | 13 | <.001 | 97.4 |
| Anxiety symptoms (T) | 8 | 8 | 0.40 | –0.09 | 0.89 | –1.08 | 1.88 | .113 | 65.98 | 8 | <.001 | 92.2 |
| PTSD symptoms (T) | 19 | 19 | 0.27 | –0.15 | 0.70 | –1.55 | 2.09 | .208 | 163.67 | 18 | <.001 | 96.1 |
| Positive MH (T) | 9 | 9 | 0.63 | –0.14 | 1.41 | –1.76 | 3.03 | .111 | 56.80 | 8 | <.001 | 98.3 |
Notes: The multilevel meta-analysis on symptom measures included psychological distress, depressive symptoms, anxiety and PTSD symptoms. Due to qualitative differences, positive MH was analysed separately and comprised measures of life satisfaction, wellbeing and quality of life. For all outcomes, SMDs were calculated in a way that positive values indicate favourable effects of an intervention (i.e. reductions of mental symptoms or increases in positive mental health).
df = degrees of freedom; I2 = heterogeneity index in percentage (range: 0% – 100%); I2S = heterogeneity accounted for by between-study differences; I2O = heterogeneity accounted for by between-outcome differences; k = number of effect sizes; MH = mental health; ML = multilevel meta-analysis, n = number of studies; PTSD = posttraumatic stress disorder; Q = Cochran’s Q statistic with p value; SMD = standardized mean difference; T = traditional meta-analysis; 95%l = lower boundary of the 95% confidence/prediction interval; 95%u = upper boundary of the 95% confidence/prediction interval.