Clinical Characteristics and Risk Factors for Mortality in Very Old Patients Hospitalized with COVID-19 in Spain

BACKGROUND Advanced age is a well-known risk factor for poor prognosis in COVID-19. However, few studies have specifically focused on very old inpatients with COVID-19. This study aims to describe the clinical characteristics of very old inpatients with COVID-19 and identify risk factors for in-hospital mortality at admission. METHODS We conducted a nationwide, multicenter, retrospective, observational study in patients ≥80 years hospitalized with COVID-19 in 150 Spanish hospitals (SEMI-COVID-19) Registry (March 1-May 29, 2020). The primary outcome was in-hospital mortality. A uni- and multivariate logistic regression was performed to assess predictors of mortality at admission. RESULTS 2,772 consecutive patients (49.4% men, median age 86.3 years) were analyzed. Rates of atherosclerotic cardiovascular disease, diabetes mellitus, dementia, and Barthel Index <60 were 30.8%, 25.6%, 30.5%, and 21.0%, respectively. The overall case-fatality rate was 46.9% (n:1,301) and increased with age (80-84 years:41.6%; 85-90 years:47.3%; 90-94 years:52.7%; ≥95 years:54.2%). After analysis, male sex and moderate-to-severe dependence were independently associated with in-hospital mortality; comorbidities were not predictive. At admission, independent risk factors for death were: SatO2 <90%; temperature ≥37.8oC; qSOFA score ≥2; and unilateral-bilateral infiltrates on chest X-rays. Some analytical findings were independent risk factors for death, including eGFR <45 ml/min/1.73m 2; lactate dehydrogenase ≥500 U/L; CRP ≥80 mg/L; neutrophils ≥7.5x10 3/μL; lymphocytes <0.8x10 3/μL; and monocytes <0.5 x 10 3/μL. CONCLUSIONS This first large, multicenter cohort of very old inpatients with COVID-19 shows that age, male sex, and poor pre-admission functional status-not comorbidities-are independently associated with in-hospital mortality. Severe COVID-19 at admission is related to poor prognosis.