: Table S1 and Table S2). The study protocol was registered in PROSPERO on June 24, 2022 . As all included data was from previously published studies, no institutional review board approval was required.We systematically searched the following electronic bibliographic databases: PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. No time or language restrictions were applied to the search results.
To be included in this systematic review, prospective or retrospective cohort studies had to meet all of the following criteria: the main exposure of interest was COVID-19, which was defined based on International Classification of Diseases codes; to determine relative associations, hospitalized or population controls were utilized as comparators, with priority given to population controls where available; report of newly diagnosed DM that was defined as the new onset of diabetes .
]. Critical appraisal was carried out by three reviewers , with discrepancies discussed with the larger authors’ group to reach a consensus.For each included study, the incidence of newly diagnosed DM was calculated using the reported number of newly diagnosed diabetes cases and person-years of follow-up. We first transformed proportions using the Freeman–Tukey double arcsine method [