Gender disparity in cases enrolled in clinical trials of visceral leishmaniasis: A systematic review and meta-analysis

Background: A higher caseload of visceral leishmaniasis (VL) has been observed among males in community-based surveys. We carried out this review to investigate how the observed disparity in gender distribution is reflected in clinical trials of antileishmanial therapies. Methods: We identified relevant studies by searching a database of all published clinical trials in VL from 1980 through 2019 indexed in the Infectious Diseases Data Observatory (IDDO) VL clinical trials library. The proportion of male participants enrolled in studies eligible for inclusion in this review were extracted and combined using random effects meta-analysis of proportion. Results were expressed as percentages and presented with respective 95% confidence intervals (95% CIs). Heterogeneity was quantified using I2 statistics and sub-group meta-analyses were carried out to explore the sources of heterogeneity. Results: We identified 135 published studies (1980–2019; 32,177 patients) with 68.0% [95% CI: 65.9%–70.0%; I2 = 92.6%] of the enrolled participants being males. The corresponding estimates were 67.6% [95% CI: 65.5%–69.7%; n = 91 trials; I2 = 90.5%; 24,218 patients] in studies conducted in the Indian sub-continent and 74.1% [95% CI: 68.4%–79.1%; n = 24 trials; I2 = 94.4%; 6,716 patients] in studies from Eastern Africa. The proportion of male participants was 57.9% [95% CI: 54.2%–61.5%] in studies enrolling children aged