The authors acknowledge the support of the Nigeria Federal Ministry of Health and the WHO Nigeria Country Office in the conduct of this study. Special thanks to Victoria Nyawira Nyaga for checking through our statistical analyses. Authorship declaration: DA conceived and designed the study. DA, DQA and AA conducted the literature searches and data extraction. DA, DQA and EOO wrote the first draft. DA and MBA conducted the analysis. DA, AA, RGM, MTD, CO, NE, MOH, WA and IFA contributed to the final draft and checked for important intellectual content. All authors approved the manuscript as submitted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.