Risk factors for mortality in patients over 70 years old with COVID-19

Background: Elderly patients with COVID-19 were shown to have a high case-fatality rate. We aimed to explore the risk factors associated with death in patients over 70 years old (yo). Methods: : In this retrospective study, we enrolled patients over 70 yo with COVID-19 between January 20 and February 15, 2020. Epidemiological, demographic, and clinical data were collected. Univariate and multivariate Cox regression methods were used to explore the risk factors. Results: : A total of 147 patients were enrolled. The case-fatality rate was 28.6%. Multivariate Cox proportional hazard regression showed that clinical subtypes including the severe type (HR = 2.983, 95% CI: 1.231–7.226, P = 0.016) and the critical type (HR = 3.267, 95%CI: 1.009–10.576, P = 0.048) were associated with increasing risk of death when compared with the general type. Blood urea nitrogen greater than 9.5 mmol/L (HR = 2.805, 95% CI: 1.141–6.892, P = 0.025) on admission was an independent risk factor for death among laboratory findings. Conclusion: The patients over 70 yo with COVID-19 had a high case-fatality rate. The risk factors including clinical subtypes and blood urea nitrogen greater than 9.5 mmol/L could help physicians to identify elderly patients with poor clinical outcomes at an early stage.