Effect sizes for the four WHOQOL domains
| k | N | d | CI | Q | I2 | |
| Physical | 24 | 2084 | 0.37 | 0.25 to 0.49 | 153.81* | 85.0 |
| Psychological | 24 | 2084 | 0.22 | 0.14 to 0.30 | 66.39* | 65.4 |
| Social | 24 | 2084 | 0.10 | 0.05 to 0.15 | 35.85** | 35.8 |
| Environment | 24 | 2084 | 0.12 | 0.06 to 0.18 | 52.76* | 56.4 |
* P<0.001, **P <0.01.
d, Cohen’s d effect size; I2, extent of heterogeneity; K, number of studies; n, number of participants; Q, significance of heterogeneity; QOL, quality of life.