Design, Conduct, Analysis, and Reporting of Therapeutic Efficacy Studies in Visceral Leishmaniasis: A Systematic Review of Published Reports, 2000–2021

A systematic review (SR) of published efficacy studies in visceral leishmaniasis (VL) was undertaken to describe methodological aspects of design, conduct, analysis, and reporting. Studies published during 2000–2021 and indexed in the Infectious Diseases Data Observatory VL library of clinical studies were eligible for inclusion (N = 89 studies). Of the 89 studies, 40 (44.9%) were randomized, 33 (37.1%) were single-armed, 14 (15.7%) were nonrandomized multiarmed studies, and randomization status was unclear in two (2.2%). After initial screening, disease confirmation was done by microscopy in 26 (29.2%) and by a combination of serology and microscopy in 63 (70.8%). Post-treatment follow-up duration was <6 months in three (3.3%) studies, 6 months in 75 (84.3%), and >6 months in 11 (12.4%) studies. Confirmation of relapse was solely based on clinical suspicion in four (4.5%) studies, parasitological demonstration in 64 (71.9%), using molecular/serological/parasitological method in 6 (6.7%), and there was no information in 15 (16.9%). Of the 40 randomized studies, sample size calculation was reported in only 22 (55.0%) studies. This review highlights substantial variations in definitions adopted for disease diagnosis and therapeutic outcomes suggesting a need for a harmonized trials protocol.