highly significantP <0.001
Heterogeneity and publication bias There was considerable heterogeneity among the included studies, such that the result of the Chi 2 test for heterogeneity was highly significant ( P <0.001).
Heterogeneity and publication bias There was considerable heterogeneity among the included studies, such that the result of the Chi 2 test for heterogeneity was highly significant ( P <0.001).
The prevalence was higher in older age groups, among females, and in the rural areas of the country, with an increasing trend in recent years.