24Background: Coronavirus disease 2019 is an emerging disease that was first reported 25 in Wuhan city, the capital of Hubei province in China, and has subsequently spread worldwide.
26Risk factors for mortality have not been well summarized. Current meta-analysis of retrospective 27 cohort studies was done to summarize available findings on the association between age, gender, 28 comorbidities and risk of death from COVID-19 infection. 29 Methods: Online databases including Web of Science, PubMed, Scopus and Google scholar were 30 searched to detect relevant publications up to 22 March 2020, using relevant keywords. To pool 31 data, random-effects model was used. Furthermore, sensitivity analysis and publication bias test 32 were also done. 33 Results: In total, six retrospective studies with 22,350 COVID-19 infected patients and 741 cases 34 of death were included in the current meta-analysis. A significant positive association was found 35 between older age (≥65 years old) and COVID-19 mortality (combined effect size=2.39 (over 36 twofold), 95% CIs=1.75-3.28, p<0.001). Such finding was also seen for hypertension (combined 37 effect size=3.29 (over threefold), 95% CIs=1.54-7.05, p=0.002), diabetes (combined effect 38 size=3.11 (over threefold), 95% CIs=1.10-8.80, p=0.032), chronic obstructive pulmonary disease 39 (COPD) (combined effect size=7.69 (over sevenfold), 95% CIs=5.65-10.47, p<0.001) and 40 cardiovascular diseases (CVDs) (combined effect size=7.39 (over sevenfold), 95% CIs=2.88-41 18.96, p<0.001).42 Conclusions: Older age, hypertension, diabetes, COPD and CVDs were associated with greater 43 risk of death from COVID-19 infection. These findings could help clinicians to identify patients 44 with poor prognosis at an early stage.45