Fig. 1

Proportion of severity endpoints among main recent studies. We performed a broad literature research in PubMed up to March 12, 2020. All articles dealing with coronavirus disease 2019 were screened. Main studies reporting characteristics and outcomes of patients affected by coronavirus disease with data referring to those with or without diabetes were extracted. Summary proportion estimates of the outcomes of interest were pooled, using inverse-variance weights obtained from a random-effects meta-analysis with 95% confidence interval. Statistical significance was set at p < 0.05. All analyses were performed in Open Meta-Analyst. In the study by Young et al., data stratified by diabetes referred to patients requiring or not requiring supplemental O2, which included but was not restricted to Intensive Care Unit (ICU)