Table 1. Glossary of key terms from the variable dictionary.

Term	Definition
Study	A study or trial, where a pre-defined protocol was followed for all participants, with the exception of differences between cohorts and arms.
Cohort	Groups within studies are considered as separate cohorts if at least one of these reasons applies: there were differences in the protocol followed for different groups of participants (other than those covered by different intervention arms); study recruitment took place in multiple distinct time periods, or participants were in different countries; participants were in a priori defined categories which depended on participant characteristics (e.g. diagnosis of different soil-transmitted helminth infections or other co-infections; ethnicity).
Arm	Different arms of a study often correspond to different drug regimens under comparison. Study- and cohort-level data are the same for different arms; only treatments/interventions vary. The arms are such that participants (or clusters, as per design) could be randomized to them (though randomization was not implemented in all studies).