Association between alcohol consumption and mild cognitive impairment: A protocol of dose-response meta-analysis.

Objective: The objective of this study is to investigate the potential dose-response association between alcohol consumption and the risk of mild cognitive impairment (MCI).

Methods: We will perform a dose-response meta-analysis (DRMA) of cohort studies to explore the dose-response relationship between alcohol intake and MCI. A comprehensive literature search of PubMed, EMBASE, The Cochrane Library, Chinese BioMedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), VIP, and Wan-Fang Database will be conducted. Two investigators will independently select studies, extract data, and assess the quality of the included study. The Newcastle-Ottawa Scale will be used to assess the quality of include studies. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system and A MeaSurement Tool to Assess systematic Reviews (AMSTAR) will be used to assess the quality of evidence and methodological quality. Any disagreement will be resolved by the third investigator. We will use the hazard ratio as the effect indicator, and piecewise linear regression model and restricted cubic spline model will be used for linear and nonlinear trend estimation, respectively. There is no requirement of ethical approval and informed consent.

Discussion: This is the first DRMA to explore the dose-response relationship between alcohol intake and MCI. We predict it will provide high-quality evidence to prevent clinical MCI and dementia.

Registration: The DRMA is registered in the PROSPERO (CRD42019127261) international prospective register of systematic review.