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).