COVID-19, Vulnerability, and Long-Term Mortality in Hospitalized and Nonhospitalized Older Persons

OBJECTIVE: Studies suggesting that vulnerability increased short-term mortality in older patients with COVID-19 enrolled hospitalized patients and lacked COVID-negative comparators. Aim of this study was to examine the relationship between frailty and 1-year mortality in older patients with and without COVID-19, hospitalized and nonhospitalized. DESIGN: Cohort study. SETTING AND PARTICIPANTS: Patients over 75 years old accessing the emergency departments (ED) were identified from the ED archives in Florence, Italy. METHODS: Vulnerability status was estimated with the Dynamic Silver Code (DSC). COVID-19 hospital discharges (HC+) were compared with non-COVID-19 discharges (HC-). Linkage with a national COVID-19 registry identified nonhospitalized ED visitors with (NHC+) or without COVID-19 (NHC-). RESULTS: In 1 year, 48.4% and 33.9% of 1745 HC+ and 15,846 HC- participants died (P < .001). Mortality increased from 27.5% to 64.0% in HC+ and from 19.9% to 51.1% in HC- across DSC classes I to IV, with HC+ vs HC- hazard ratios between 1.6 and 2.2. Out of 1039 NHC+ and 18,722 NHC- participants, 18% and 8.7% died (P < .001). Mortality increased from 14.2% to 46.7% in NHC+ and from 2.9% to 26% in NHC- across DSC; NHC+ vs NHC- hazard ratios decreased from 5.3 in class I to 2.0 in class IV. CONCLUSIONS AND IMPLICATIONS: In hospitalized older patients, mortality increases with vulnerability similarly in the presence and in the absence of COVID-19. In nonhospitalized patients, vulnerability-associated excess mortality is milder in individuals with than in those without COVID-19. The disease reduces survival even when background risk is low. Thus, apparently uncomplicated patients deserve closer clinical monitoring than commonly applied.