Table 2.
Results of the univariate meta-regression analysis on the heterogeneity of the determinants
| Variables | Sample size | |
|---|---|---|
| Coefficient (95% CI) | p value | |
| Publication year | 0.033 (0.009 to 0.057) | 0.011* |
| Sample size | −0.001 (−0.002 to 0.001) | 0.077 |
| Device | −0.001 (−0.023 to 0.021) | 0.940 |
*: Significance.
Code for device: 1 – exposure to magnetic field of high-voltage power line; 2 – exposure to RF of cell phone, Wi-Fi, and radio transmitters; 3 – prenatal exposure to diagnostic X-ray; and 4 – exposure to ultrasound and shortwave devices.