Self-medication prevalence for sexually transmitted diseases: meta-analysis and meta-regression of population level determinants.

BACKGROUND: Estimated prevalence of self-medication for sexually transmitted diseases (STDs) in observational studies differs between studies and it may vary according to population characteristics. METHODS: We investigated the extent of self-medication use for STD and explored population and study level factors correlated to the variability observed between populations. Medical databases were systematically searched for published studies. Crude prevalence data were extracted. Pooled estimates were calculated using random effects models. Univariate and multivariate meta-regression models with categorical population level covariates were constructed. RESULTS: Of the 35 studies that met the inclusion criteria for all self-medication use, 20 were also included in the analysis of antibiotic only use. There was significant heterogeneity present across prevalence estimates for all self-medication, Q = 3954.82, P <0.001; and among antibiotic only self-medication, Q = 3797.94, P <0.001. In meta-regression analyses, publication year seemed to explain 22.5% of variation among studies of self-medication with antibiotic only. No other significant associations with population or study characteristics were found. CONCLUSIONS: No population level factors leading to high levels of self-medication use for STD were identified. Publications before year 2000 seem to present a higher prevalence of antibiotic use for self-medication. Greater risk awareness of antibiotic misuse and improved control of antibiotic availability at population level might explain this result. An analysis of individual level characteristics should indicate which are influential and whether their local prevalence can explain the observed heterogeneity better.