Table 3. Meta- regression analysis.
| Variables | Univariate | Multivariate |
|---|---|---|
| Β (95%CI), p | Β (95%CI), p | |
| RCT study design | ||
| Quality (ref: ≥5 vs <5) | 0.09 (-0.19 to 0.38), 0.916 | |
| Intensity of intervention (min/d) | -0.002 (-0.008, 0.003), 0.39 | |
| Frequency of intervention (times/wk) | 0.06 (-0.05 to 0.16), 0.27 | |
| Length of intervention (wks) (continuous) | -0.002 (-0.01 to 0.01), 0.69 | |
| Sample type (ref: non-normal vs normal) | 0.10 (-0.27 to 0.46), 0.60 | |
| Setting of intervention (ref: clinc/detention facility/family vs school/gymnasium) | 0.31 (0.07 to 0.55), 0.013 | 0.31 (0.03 to 0.55), 0.068 |
| Non-RCT study design | ||
| Quality (ref: ≥6 vs <6) | -0.07 (-0.57 to 0.42), 0.75 | |
| Intensity of intervention (min/d) | 0.00 (-0.01 to 0.01), 0.86 | |
| Frequency of intervention (times/wk) | 0.03 (-0.14 to 0.19), 0.74 | |
| Length of intervention (wks) (continuous) | -0.01 (-0.03 to 0.01), 0.39 | |
| Sample type (ref: non-normal vs normal) | 0.15 (-0.36 to 0.67), 0.53 | |
| Setting of intervention (ref: clinc/detention facility/family vs school/gymnasium) | -0.12 (-0.84 to 0.60), 0.73 | |
B, regression coefficient; RCT, randomized controlled trial; Non-RCT, non-randomized controlled trial; Ref, reference category.
No significant association was found between effect sizes and intensity of intervention, frequency of intervention, length of intervention, participant type, and study quality in RCTs, as well as all assessed factors in non-RCTs.