Gray literature in systematic reviews on population health in the Middle East and North Africa: protocol of an overview of systematic reviews and evidence mapping.

BACKGROUND: Systematic review (SR) guidelines recommend extending literature search to gray literature in order to identify all available data related to the review topic. We aim to conduct an overview of SRs on population health in the Middle East and North Africa (MENA), to assess the methodology of these SRs, to produce an evidence map highlighting methodological gaps in SRs regarding gray literature searching, and to aid in developing future SRs by listing gray literature sources related to population health in MENA.

METHODS/DESIGN: We will conduct an overview of SRs based on the Cochrane Handbook for Systematic Reviews of Interventions. This overview will be reported following PRISMA 2009 guidelines. Using comprehensive search criteria, we will search the PubMed database to identify relevant SRs published since 2008. Our primary outcomes are gray literature sources and study-level quality in the gray literature. We will include MENA countries with Arabic, English, French, and/or Urdu as primary official languages and/or media of instruction in universities. Two reviewers will independently conduct a multilevel screening on Rayyan software. Extraction of relevant data will be done on Statistical Package for the Social Sciences (SPSS) software. The methodological quality of included SRs will be assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) tool. Any disagreements will be resolved by discussion and consensus. We will estimate the overall proportion of SRs that used gray literature as one of their data sources. Subgroup analyses will be conducted to identify characteristics of these gray literature sources. Chi-squared and t tests will be used to determine whether the differences between subgroups are statistically significant. Additionally, an evidence gap map will be constructed to highlight characteristics and quality of the gray literature used in SRs on population health in MENA and emphasize existing gaps in gray literature searching. We will also list gray literature sources identified in the included SRs stratified by country and research topic.

DISCUSSION: This overview will comprehensively assess the overall quality of the SRs on population health issues in MENA. Our findings will contribute to the improvement of population health research practices in MENA.

SYSTEMATIC REVIEW REGISTRATION: The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 26 October 2018 (registration number CRD42017076736 (Syst Rev 2:4, 2013).