Continent | Prevalence | I-squared | Number of studies |
---|---|---|---|
Grouping variable | |||
 Asia | 4.56 (2.51–7.15) | 97.2 | 14 |
 Africa | 14.34 (9.48–19.97) | 69.44 | 2 |
 Europe | 6.16 (3.30–9.80) | 95.56 | 9 |
 America | 7.39 (2.34–14.84) | 92.71 | 3 |
Design | |||
 Cohort | 4.98 (2.07–9.02) | 97.77 | 10 |
 Case-control | 2.66 (1.7–3.81) | 82.01 | 4 |
 Cross-sectional | 6.52 (3.67–10.09) | 97.38 | 16 |