Older age and frailty are the chief predictors of mortality in COVID-19 patients admitted to an acute medical unit in a secondary care setting- A cohort study

Background There is a need for more observational studies across different clinical settings to better understand the epidemiology of the novel COVID-19 infection. Evidence on clinical characteristics of COVID-19 infection is scarce in secondary care settings in Western populations. Methods We describe the clinical characteristics of all consecutive COVID-19 positive patients (n=215) admitted to the acute medical unit at Fairfield General Hospital (secondary care setting) between 23 March 2020 and 30 April 2020 based on the outcome at discharge (group 1: alive or group 2: deceased). We investigated the risk factors that were associated with mortality using binary logistic regression analysis. Kaplan-Meir (KM) curves were generated by following the outcome in all patients until 12 May 2020. Results The median age of our cohort was 74 years with a predominance of Caucasians (87.4%) and males (62%). Of the 215 patients, 86 (40%) died. A higher proportion of patients who died were frail (group 2: 63 vs group 1: 37%, p<0.001), with a higher prevalence of cardiovascular disease (group 2: 58 vs group 1: 33%, p<0.001) and respiratory diseases (group 2: 38 vs group 1: 25 %, p=0.03). In the multivariate logistic regression models, older age (odds ratio (OR) 1.03; p=0.03), frailty (OR 5.1; p<0.001) and lower estimated glomerular filtration rate (eGFR) on admission (OR 0.98; p=0.01) were significant predictors of inpatient mortality. KM curves showed a significantly shorter survival time in the frail older patients. Conclusion Older age and frailty are chief risk factors associated with mortality in COVID-19 patients hospitalised to an acute medical unit at secondary care level. A holistic approach by incorporating these factors is warranted in the management of patients with COVID-19 infection.