Risk factors for mortality in patients over 70 years old with COVID-19 in Wuhan at the early break: retrospective case series

Zhu, Xu; Yuan, Wenzheng; Shao, Junwei; Huang, Kesheng; Wang, Qingbo; Yao, Shuang; Lu, Wei; Liu, Li; Fu, Tao

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 (yr). METHODS: In this retrospective study, we enrolled consecutively hospitalized patients over 70 yr with COVID-19 between January 20 and February 15, 2020 in Renmin Hospital of Wuhan University. Epidemiological, demographic, and clinical data were collected. Clinical subtypes, including mild, moderate, severe, and critical types, were used to evaluate the severity of disease. Patients were classified into two groups: survivor and non-survivor groups. Clinical data were compared between the two groups. Univariable and multivariable 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%. Multivariable 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 yr 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. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-021-06450-8.