Data collection and study variables
The following variables were collected and analysed: demographic data, cardiovascular risk factors, comorbidities, clinical presentation, analytical and radiological abnormalities (chest radiography, computed tomography -CT- and/or lung ultrasound -LUS-) and prescribed treatment during admission. The burden of comorbidities and one-year risk of death was calculated using the PROFUND score, that includes demographic, clinical, laboratory, social and functional variables, and establishes 4 levels of risk of death: low, intermediate, high and very high10. LUS abnormalities were classified using a score similar to that of Soldati et al11. Finally, we collected information about the outcome after admission (discharge, death, or transfer to the ICU).