In-hospital mortality prediction using frailty scale and severity score in elderly patients with severe COVID-19

BACKGROUND: Elderly patients with coronavirus disease 2019 (COVID-19) have a high disease severity and mortality. However, the use of the frailty scale and severity score to predict in-hospital mortality in the elderly is not well established. Therefore, in this study, we investigated the use of these scores in COVID-19 cases in the elderly. METHODS: This multicenter retrospective study included severe COVID-19 patients admitted to seven hospitals in Korea from February 2020 to February 2021. We evaluated patients’ Acute Physiology and Chronic Health Evaluation (APACHE) II score; confusion, urea nitrogen, respiratory rate, blood pressure, 65 years of age and older (CURB-65) score; modified early warning score (MEWS); Sequential Organ Failure Assessment (SOFA) score; clinical frailty scale (CFS) score; and Charlson comorbidity index (CCI). We evaluated the predictive value using receiver operating characteristic (ROC) curve analysis. RESULTS: The study included 318 elderly patients with severe COVID-19 of whom 237 (74.5%) were survivors and 81 (25.5%) were non-survivors. The non-survivor group was older and had more comorbidities than the survivor group. The CFS, CCI, APACHE II, SOFA, CURB-65, and MEWS scores were higher in the non-survivor group than in the survivor group. When analyzed using the ROC curve, SOFA score showed the best performance in predicting the prognosis of elderly patients (area under the curve=0.766, P<0.001). CFS and SOFA scores were associated with in-hospital mortality in the multivariate analysis. CONCLUSIONS: The SOFA score is an efficient tool for assessing in-hospital mortality in elderly patients with severe COVID-19.