Table 9.
Multiple meta-regression analysis, predicting between-study variance in unidimensional outcomes using the level of similarity between active and sham control groups for a number of selected features in large trials of psychological and behavioural interventions.
| Descriptives | |||||||
|---|---|---|---|---|---|---|---|
| Mean ES | Mean (SD) similarity rating (application mode) | Mean (SD) similarity rating (attention focus/cognitive function) | R 2 | k | |||
| −0.33 | 0.84 (1.7) | −0.26 (1.6) | 0.41 | 19 | |||
| Homogeneity analysis | |||||||
|---|---|---|---|---|---|---|---|
| Q | Df | P | T 2 | I2 | |||
| Model | 11.48 | 2 | 0.0032 | 0.02 | 82.6% | ||
| Residual | 16.3 | 16 | 0.4222 | 0.00 | 1.8% | ||
| Total | 27.78 | 18 | 0.0654 | ||||
| Regression coefficients | |||||||
|---|---|---|---|---|---|---|---|
| B | SE | −95% CI | +95% CI | Z | P | Beta | |
| Constant | −0.4 | 0.08 | −0.55 | −0.24 | −4.97 | 0.0000 | 0.0 |
| Similarity: attention | 0.09 | 0.04 | 0.006 | 0.17 | 2.1 | 0.036 | 0.41 |
| Similarity: application mode | 0.09 | 0.04 | 0.002 | 0.17 | 2. | 0.045 | 0.41 |
| Method of moments random effects variance component | |||||||
| v = 0.03 | |||||||
Means and variance of the similarity ratings included in the model are provided, having a possible range of −2 (different for all studies) to 2 (similar across all studies).