An arm-based network meta-analysis on treatments for vulvar lichen sclerosus and a call for development of core outcome sets

Abstract

Objective: The purpose of the present systematic review is to evaluate the available medical treatments for vulvar lichen sclerosus, using an arm-based network meta-analysis protocol.

Data sources: We searched Medline (1966-2019), Scopus (2004-2019), Cochrane Central Register of Controlled Trials CENTRAL (1999-2019), Clinicaltrials.gov (2008-2019) databases, and Google Scholar (2004-2019) database along with the reference list of all included studies.

Study eligibility criteria: All observational, randomized, and single-arm studies that evaluated medical treatments for vulvar lichen sclerosus were considered eligible for inclusion in the present systematic review.

Study appraisal: A network meta-analysis was carried out in R 3.4.3 using the pcnetmeta package, which uses a Bayesian hierarchical model (based in Markov chain Monte Carlo convergence simulation).

Results: Sixteen studies were included in this present meta-analysis, which recruited 954 women with vulvar lichen sclerosus. Their quality was evaluated with the JADAD, Cochrane risk of bias, and risk of bias in nonrandomised studies of interventions-I tools. Clobetasol treatment ranked as the best treatment for disease remission after evaluating rank probabilities (40% chance of ranking first compared with tacrolimus [38%]). However, the density plot revealed partial overlapping with tacrolimus. The lowest probability of experiencing a relapse was observed with pimecrolimus (15% [2-48%]); however, the density plot revealed significant overlapping with mometasone furoate, testosterone, and clobetasol.

Conclusion: Robust evidence concerning the superiority of potent steroids at least over calcineurin inhibitors is still lacking in the field of vulvar lichen sclerosus. On the other hand, the gross heterogeneity in terms of selected population, duration of treatment, administered regimen, outcome reporting, and selection of outcome measures leaves several fields unanswered.

Keywords: clobetasol; lichen sclerosus; meta-analysis; network; tacrolimus; vulvar.