Comparison of the effect of dietary and herbal supplements on anthropometric, metabolic and androgenic profiles of women with polycystic ovary syndrome: a systematic review and network meta-analysis protocol

Polycystic ovarian syndrome (PCOS) is characterized by obesity, glucose intolerance, dyslipidemia, and hyperandrogenemia. Although several, placebo-controlled 2x2 factorial design, randomized controlled trials have tested the efficacy of dietary and herbal supplements in controlling these parameters in PCOS patients, these studies are not suitable for a comparative efficacy assessment across these supplements. Herein, a protocol for systematic review and network meta-analysis (NMA) is presented to make such a comparison. PubMed, Embase, and Scopus, were interrogated to identify relevant trials, published in English, factors to be investigated will include dietary factors, micronutrients, choline, essential fatty acids, and herbal extracts. Other factors to be considered include trial design, population characteristics, interventions compared, and outcomes of interest. The revised Cochrane tool was used for the appraisal of eligible trials. NMA (frequentist method) will be used for respective outcomes to compare effect sizes (weighted or standardized mean difference) among the interventions. Both logical and statistical (inconsistency assessment) approaches will be used to minimize intransitivity risk. The surface under the cumulative ranking curve values will be used to gauge the best intervention for outcomes with a statistically significant effect size suggesting a favorable outcome. Additionally, the exploration of interrelation among interventions and the small study effect in respective NMA models will be investigated using network maps and comparison-adjusted funnel plots, respectively. Statistical significance is assumed at p<0.05 with 95% confidence interval. Stata statistical software (v16) was used for analysis.