Association between ABO blood groups and risk of coronavirus disease 2019: A protocol for systematic review and meta-analysis

BACKGROUND: The 2019 Coronavirus Disease (COVID-19) pandemic has threatened millions of people worldwide. Growing evidence suggests that the ABO blood type contributed to the susceptibility of COVID-19, but the results are controversial. The major objective of this systematic review and meta-analysis study is to investigate the impact of ABO blood group on COVID-19 pneumonia. METHODS: Two independent reviewers searches the databases of the China Biology Medicine disc, China National Knowledge Infrastructure, China Science and Technology Periodical Database, Wanfang Database, PubMed, Embase, and Web of Science from the date of conception to June 30, 2020. We will manually search for gray literature, such as meeting records and dissertations. Two independent reviewers will screen studies that meet the criteria, extract data, statistical data, and assess the risk of bias. The dichotomous variable will calculate the odds ratio and the corresponding 95% confidence interval. Heterogeneity between included studies will be assessed by heterogeneity χ(2) tests and I(2) index. The forest plots will be used to describe the pooled results. The Begg rank correlation test or Egger linear regression test will be performed to quantize the publication bias. DISCUSSION: This study will provide high-quality evidence to evaluate the contribution of the ABO blood group in COVID-19 pneumonia infection. PROSPERO REGISTRATION NUMBER: CRD42020195615