Novelli L, Raimondi F, Ghirardi A, Pellegrini D, Capodanno D, Sotgiu G, Guagliumi G, Senni M, Russo FM, Lorini FL, Rizzi M, Barbui T, Rambaldi A, Cosentini R, Grazioli LS, Marchesi G, Sferrazza Papa GF, Cesa S, Colledan M, Civiletti R, Conti C, Casati M, Ferri F, Camagni S, Sessa M, Masciulli A, Gavazzi A, Falanga A, DA Pozzo LF, Buoro S, Remuzzi G, Ruggenenti P, Callegaro A, D'Antiga L, Pasulo L, Pezzoli F, Gianatti A, Parigi P, Farina C, Bellasi A, Solidoro P, Sironi S, DI Marco F, and Fagiuoli S
Background: Findings from February 2020, indicate that the clinical spectrum of COVID-19 can be heterogeneous, probably due to the infectious dose and viral load of SARS-CoV-2 within the first weeks of the outbreak. The aim of this study was to investigate predictors of overall 28-day mortality at the peak of the Italian outbreak., Methods: Retrospective observational study of all COVID-19 patients admitted to the main hospital of Bergamo, from February 23 to March 14, 2020., Results: Five hundred and eight patients were hospitalized, predominantly male (72.4%), mean age of 66±15 years; 49.2% were older than 70 years. Most of patients presented with severe respiratory failure (median value [IQR] of PaO2/FiO2: 233 [149-281]). Mortality rate at 28 days resulted of 33.7% (N.=171). Thirty-nine percent of patients were treated with continuous positive airway pressure (CPAP), 9.5% with noninvasive ventilation (NIV) and 13.6% with endotracheal intubation. 9.5% were admitted to Semi-Intensive Respiratory Care Unit, and 18.9% to Intensive Care Unit. Risk factors independently associated with 28-day mortality were advanced age (≥78 years: odds ratio [OR], 95% confidence interval [CI]: 38.91 [10.67-141.93], P<0.001; 70-77 years: 17.30 [5.40-55.38], P<0.001; 60-69 years: 3.20 [1.00-10.20], P=0.049), PaO2/FiO2<200 at presentation (3.50 [1.70-7.20], P=0.001), need for CPAP/NIV in the first 24 hours (8.38 [3.63-19.35], P<0.001), and blood urea value at admission (1.01 [1.00-1.02], P=0.015)., Conclusions: At the peak of the outbreak, with a probable high infectious dose and viral load, older age, the severity of respiratory failure and renal impairment at presentation, but not comorbidities, are predictors of 28-day mortality in COVID-19.