Strengthening literature search strategies for systematic reviews reporting population health in the Middle East and North Africa: A meta-research study.

OBJECTIVE: In the Middle East and North Africa (MENA), data are produced in languages other than English and available through gray literature sources. We assessed the comprehensiveness of literature search strategies of systematic reviews (SRs) reporting population health primary data on MENA.

METHODS: Utilizing the registered protocol (PROSPERO CRD42017076736), we conducted a meta-research analysis on a cohort of SRs (systematic PubMed search: from 2008 to 2016) and evaluated their search strategies following AMSTAR recommendations.

RESULTS: A total of 379 SRs were included. Few SRs (10.3%, n = 39) conducted a comprehensive literature search including at least two databases, reference lists of included primary studies, gray literature sources, and no language restriction. Nevertheless, 90.5% (n = 343) searched at least two databases and 67.0% (n = 254) searched gray literature sources. Authors from MENA searched statistically more for gray literature than authors from Western countries (P = 0.022). Reference lists of the included studies were searched in 40.4% (n = 153) of the SRs. Searching the reference lists was positively associated with searching for gray literature (P < 0.001). Only 38.8% (n = 147) of the SRs had no language restriction or searched in English and in at least one language relevant to MENA, whereas 27.2% (n = 103) did not report this information.

CONCLUSIONS: Literature searches for SRs reporting population health data on MENA were limited in reporting quality, language restrictions, and lack of reference list searches. This was probably due to lack of adherence to the reporting guidelines. To ensure compilation of optimum evidence, expanding literature searches to reference list search and for additional languages relevant to MENA are required.