Abstract
INTRODUCTION: Preserving cognitive health is a crucial aspect of healthy ageing. Both abnormal and normal cognitive decline can adversely affect the health of ageing populations. Evidence suggests religious involvement (RI) can preserve cognition in ageing populations. The primary purpose of this review is to examine the evidence regarding the association between RI and cognition from a life-course perspective. METHODS AND ANALYSIS: This systematic review and meta-analysis has been registered with PROSPERO (registration number CRD42016032331). We will search MEDLINE, PSYCHINFO and EMBASE, and include primary studies with a comparison group, for example, cohort, cross-sectional and case-control studies. To supplement the database search, we will also search the grey literature and the reference lists of included studies. Two reviewers will independently assess and extract data from the articles. Risk of bias and the strength of evidence will be assessed. For sufficiently homogeneous data in domains such as study methods and measures of RI and cognition, we will pool the results using DerSimonian and Laird meta-analysis. ETHICS AND DISSEMINATION: Since this is a protocol for a systematic review, ethics approval is not required. The findings of this review will be extensively disseminated through peer-reviewed publications and conference presentations.