The effect of diabetes on mortality of COVID-19: A protocol for systematic review and meta-analysis.

Background: Novel coronavirus pneumonia (COVID-19) is a very serious and urgent infectious disease. With the development of global economy and the improvement of living standard, the incidence of diabetes is increasing year by year. And it is more common in the elderly. COVID-19 is associated with much chronic disease, especially diabetes. At present, there is no systematic review and meta-analysis of mortality based on large scale of data between diabetes and COVID-19 all over the world. Methods and analysis: The databases of PubMed, the Cochrane Library, EMBASE, Wanfang Data, China National Knowledge Infrastructure database (CNKI) and VIP were searched by computer, and the researches related to diabetes mellitus and mortality of COVID-19 were collected. The searching time was from the establishment of the database to April 30 2020. The meta-analysis was carried out by Review Manager Version 5.3 and stata 14.0 software for Mac software after 2 researchers independently selected literature, extracted data and evaluated the bias risk. The main outcome was the mortality of COVID-19 which was included in meta-analysis and subgroup analysis. The bias of the study was evaluated independently by NOS scale, and published by funnel chart. The sensitivity was analyzed row by row. Results: The results will be published at a peer-reviewed journal. Registration number: INPLASY202040158.