Table 2.
Comparison the indicators of studies across continents
| Group | Number studies | Effect size and 95% confidence interval | Test of null (2-tail) | Heterogeneity | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| OR | Lower limit | Upper limit | Z-value | P-value | Q-value | df (Q) | P-value | I-squared | ||
| Far East | 3 | 0.82 | 0.36 | 1.86 | 0.46 | 0.64 | 2.16 | 2 | 0.33 | 7.63 |
| Middle East | 9 | 1.38 | 0.83 | 2.32 | 1.25 | 0.21 | 24.37 | 9 | 0.00 | 63.08 |
| Europe | 6 | 2.86 | 0.90 | 9.02 | 1.79 | 0.07 | 22.18 | 5 | 0.00 | 77.46 |
| Africa | 3 | 1.44 | 0.27 | 7.73 | 0.43 | 0.66 | 6.93 | 2 | 0.03 | 71.15 |
| Total | 22 | 1.55 | 1.01 | 2.38 | 2.01 | 0.04 | 63.58 | 21 | 0.00 | 66.97 |