Fig 4. Characteristics of comparative and multi-arm studies collecting data on the efficacy of drugs for treating ascariasis, trichuriasis and hookworm.

The left-hand bar shows that of 129 studies, 82 (64%) were assessed as having a comparative aspect. For randomization (middle bar) and blinding (right-hand bar), the bars show (from bottom to top) single arm studies; multi-arm studies in which no randomization/blinding was reported; multi-arm studies where randomization/blinding was reported but with no details of randomization method or of who was blinded, and finally studies where randomization/blinding was reported and details of the method/who was blinded were given.