Absence of negativization of nasal swab test and frailty as risk factors for mortality in elderly COVID-19 patients admitted in long-term care facilities

Abstract

Methods: A limited amount of data is now available on prognostic factors and mortality among elderly people resident in Long-Term Care facilities and in post-acute units. These populations (in particular those with underlying chronic medical conditions) seem to have higher risk of morbidity and mortality related to COVID-19 disease, but further evidence is needed. The aim of our study is to investigate the impact of some well-known prognostic factors in elderly patients (≥ 65 years) with COVID-19 admitted in the Long-Term Care setting in AUSL Ferrara, Italy. We performed binary regression logistic analysis for some variables (demographic data, clinical data including nasal swab test (NST) at discharge and frailty assessments) to find potential predictors of mortality. We subsequently tested statistically significant variables using Kaplan–Meier curves and Cox-regression models to find survival outcomes and related hazard ratio. Results: Risk factors associated with increased mortality resulted NST at discharge, infection, age and frailty. At a further secondary analysis carried out between NST at discharge, age and clinical frailty scale (CFS) < 5, we found a positive correlation between NST at discharge and CFS < 5. Kaplan–Meier curves showed a statistically significant difference regarding frailty and NST at discharge but not for age. Conclusion: Our study showed that absence of negativization of NST at discharge and frailty are strong predictors for mortality in elderly COVID-19 patients admitted in Long-Term Care facilities, while age and the comorbidity burden are less important.