Statistical analysis
A proportional meta-analysis was performed to calculate a pooled effect estimate in the overall population. A pooled proportion (i.e., prevalence) and pooled odds ratio (OR) with their 95% CI were computed with random effects models for the overall populations and various subgroups. The models showing significant between-study heterogeneity were presented. Moreover, the heterogeneity was assessed using Cochran’s Q and I2 statistics. Forest plots were constructed to present the study results visually. Statistical analysis was performed using the Stata software version 14 (Stata Corporation, College Station, TX, USA).