Introduction: COVID-19 is a potentially life-threatening disease, particularly in older adults with comorbidities, associated to a high incidence of hospitalization and in-patients mortality. There are few studies that describe mortality and risk factors after one year follow up.

Methods: We analyzed clinical data, mortality, and calculated age-adjusted Charlson Comorbidity Index (ACCI) of 15 years and older COVID-19 patients hospitalized with acute respiratory failure, and for a period of one year after admission to the Regional Hospital of Arica, the only center for a region of 200.000 habitants. Then a multivariable analysis was conducted.

Results: 1 064 patients were admitted for SARS-COV2 infection and acute respiratory failure. 664 were male (62.4%), median (IQR) age was 56 (43-68) years, and median (IQR) ACCI was 2 (0-3). The overall hospital mortality was 18%, and 3.9% among survivors one year post admission. The multivariable analysis identified 5 risk factors for hospital mortality: ACCI (OR 10.7; 95%CI 6.6-17.3), anemia (OR 2.0; 95%CI 1.3-3.3), thrombocytopenia (OR 2.8; 95%CI 1.7-4.7), high-flow nasal cannula (OR 5; 95%CI 2.5-9.9) and mechanical ventilation (OR 3.1; 95%CI 1.9-5.0). The post discharge mortality risk factors were ACCI (OR 17.2; 95%CI 4.8-61.1), anemia (OR 3.8; 95%CI 1.5-9.8), thrombocytopenia (OR 5.1; 95%CI 2.1-16.5) and a normal LDH (OR 4.4; 95%CI 1.5-12.9).

Conclusions: Age and comorbidities were the most important risk factors to predict in-hospital and after discharge mortality. Unlike mortality during hospitalization, patients with ventilatory support didn?t have worse outcomes than the rest of the patients after one year follow up.