Chronic diseases, chest computed tomography, and laboratory tests as predictors of severe respiratory failure and death in elderly Brazilian patients hospitalized with COVID-19: a prospective cohort study

Background The primary risk factors for severe respiratory failure and death in the elderly hospitalized with COVID-19 remain unclear. Objective To determine the association of chronic diseases, chest computed tomography (CT), and laboratory tests with severe respiratory failure and mortality in older adults hospitalized with COVID-19. Method This was a prospective cohort with 201 hospitalized older adults with COVID-19. Chronic diseases, chest CT, laboratory tests, and other data were collected within the first 48 h of hospitalization. Outcomes were progression to severe respiratory failure with the need of mechanical ventilation (SRF/MV) and death. Results The mean age was 72.7 ± 9.2 years, and 63.2% were men. SRF/MV occurred in 16.9% ( p < 0.001), and death occurred in 8%. In the adjusted regression analyses, lung involvement over 50% [odds ratio (OR): 3.09 (1.03–9.28; 0.043)], C-reactive protein (CRP) > 80 ng/mL [OR: 2.97 (0.99–8.93; 0.052)], Vitamin D < 40 ng/mL [OR: 6.41 (1.21–33.88; 0.029)], and hemoglobin < 12 g/mL [OR: 3.32 (1.20–9.20; 0.020)] were independent predictors for SFR/MV, while chronic atrial fibrillation [OR: 26.72 (3.87–184.11; 0.001)], cancer history [OR:8.32 (1.28–53.91; 0.026)] and IL-6 > 40 pg/mL [OR:10.01 (1.66–60.13; 0.012)] were independent predictors of death. Conclusion In hospitalized older adults with COVID-19, tomographic pulmonary involvement > 50%, anemia, vitamin D below 40 ng/mL, and CRP above 80 mg/L were independent risk factors for progression to SRF/MV. The presence of chronic atrial fibrillation, previous cancer, IL-6 > 40 pg/mL, and anemia were independent predictors of death.