Data Collection, Risk of Bias Assessment, and Data Analyses
The reviewers independently extracted data from the included studies using a standardized data collection form based on RevMan v5.3. More specifically, the following data were extracted: inclusion and exclusion criteria of the study population, age, sex, recruitment, follow up, intervention and control, and outcomes of interest. In cases where study data are deemed unclear or ambiguous, study authors were contacted for clarifications.
In assessing included studies for bias, the Cochrane Collaboration Tool Risk of Bias Tool were used to evaluate the following: randomization method, method of allocation concealment, attrition bias, blinding of both study subjects and personnel, blinding of outcome assessors, intention-to-treat analysis, and other biases. The RevMan v5.3 software was used to analyze the data extracted from the studies. Depending on the available collective data, prespecified subgroup analyses as stated in the objectives of the meta-analysis were done. Forest plot analyses were used to demonstrate the magnitude of treatment effects in terms of the outcomes of interest. Heterogeneity testing using I2, Chi-square tests, were also accomplished