Table 3. Pooled estimate and heterogeneity in subgroups analyses.
| Subgroup analysis | No. of trails | No. of subjects | Pooled estimate (SMD, 95% CI) | Heterogeneity | ||
|---|---|---|---|---|---|---|
| ADHD | Controls | I2 | P-value | |||
| Treatment | ||||||
| Without treatment | 8 | 516 | 366 | -0.36 (-0.72 to 0.00) | 82.6 | <0.001 |
| Under treatment | 3 | 50 | 57 | -0.29 (-1.26 to 0.68) | 80.9 | 0.005 |
| Comorbid | ||||||
| Yes | 5 | 207 | 175 | -0.42 (-1.06 to 0.22) | 82.2 | 0.001 |
| No | 4 | 359 | 200 | -0.48 (-0.94 to -0.01) | 86.6 | <0.001 |
| Assay method | ||||||
| ELISA | 4 | 237 | 170 | -0.78 (-1.48 to -0.07) | 89.8 | <0.001 |
| Others | 5 | 911 | 787 | -0.21 (-0.51 to 0.09) | 73.4 | 0.005 |