Table 3.
Summary of meta-regression results for the 90 included studies.
| Regression Variables | Number of Studies | Random Effect Pooled Prevalence (95% CI) | I2 (%) | τ2 | P-value |
|---|---|---|---|---|---|
| 1) Continent | |||||
| Asia-Pacific | 66 | 0.04 (0.03–0.06) | 62.37 | 0.0015 | 0.04* |
| Europe | 15 | 0.22(0.17–0.28) | |||
| North America | 9 | 0.05 (0.04–0.06) | |||
| 2) Country | |||||
| China | 63 | 0.04 (0.03–0.06) | 46.74 | 0.0011 | <0.001* |
| Other Countries | 27 | 0.13 (0.11–0.16) | |||
| 3) Age Group (Years) | |||||
| ≤60 | 54 | 0.05 (0.03–0.06) | 70.49 | 0.0016 | 0.2 |
| >60 | 36 | 0.10 (0.07–0.14) | |||
| 4) Study Design | |||||
| Cohort | 64 | 0.07 (0.05–0.09) | 57.22 | 0.0015 | 0.35 |
| Non-Cohort | 26 | 0.07 (0.05–0.09) | |||
| 5) Sample Size | |||||
| ≤100 | 54 | 0.10 (0.07–0.14) | 70.17 | 0.0015 | 0.075 |
| >100 | 36 | 0.05 (0.04–0.07) | |||
Note: I2, percent residual variation due to heterogeneity; τ2, residual maximum likelihood estimates of between-study variance; CI, confidence interval.