Variable	Definition	Type of Variable and Values
Demographics
Age	Age in years at hospital admission.	Continuous. Numerical.
Race	Race of the patient.	Categorical. Caucasian, Latin, or other.
Sex	Sex of patient at birth.	Categorical. Male or female.
Comorbidities
Age-adjusted Charlson index	Charlson Comorbidity Index calculated at hospital admission, based on comorbidity previously reported in medical history adjusted for age.	Continuous. Numerical, 0–48.
AMI	If acute myocardial infarction was previously reported in the medical history.	Categorical. Yes or no.
Alcohol abuse	If alcohol abuse was reported in the medical history.	Categorical. Yes or no.
Angina	If angina was previously reported in the medical history.	Categorical. Yes or no.
Asthma	If asthma was previously reported in the medical history.	Categorical. Yes or no.
Atrial fibrillation	If atrial fibrillation was previously reported in the medical history.	Categorical. Yes or no.
Cancer	If active cancer was reported in the medical history.	Categorical. Yes or no.
Comorbidity	Age-adjusted Charlson score value ≥ 3	Categorical. Yes or no.
COPD	If chronic obstructive pulmonary disease was previously reported in the medical history.	Categorical. Yes or no.
Dependence status	What was the degree of dependence before hospital admission reported in the medical history according to the Barthel index?	Categorical. Absent or mild dependence, moderate dependence, or severe dependence.
Depression	If chronic depression was previously reported in the medical history.	Categorical. Yes or no.
CHF	If chronic heart failure was previously reported in the medical history.	Categorical. Yes or no.
CHT	If chronic hypertension was previously reported in the medical history.	Categorical. Yes or no.
CKD	If chronic kidney disease, defined as MDRD4 <60 mL/min (1.73 m2), was previously reported in the medical history.	Categorical. Yes or no.
CLD	If chronic liver disease was previously reported in the medical history.	Categorical. Yes or no.
CTD	If a connective tissue disease (e.g., systemic lupus erythematosus and scleroderma) was previously reported in the medical history.	Categorical. Yes or no.
DM	If diabetes mellitus was previously reported in the medical history.	Categorical. Yes or no.
Dyslipidemia	If dyslipidemia was previously reported in the medical history.	Categorical. Yes or no.
IS	If ischemic stroke was previously reported in the medical history.	Categorical. Yes or no.
Neurodegenerative disease	If a neurodegenerative disease (e.g., Alzheimer disease, Parkinson disease, and Huntington disease) was previously reported in the medical history.	Categorical. Yes or no.
Obesity	If obesity, defined as a body mass index >30 kg/m2, was previously reported in the medical history.	Categorical. Yes or no.
OSAS	If obstructive sleep apnea syndrome was previously reported in the medical history.	Categorical. Yes or no.
PVD	If peripheral vascular disease was previously reported in the medical history.	Categorical. Yes or no.
Smoking	If smoking was previously reported in the medical history.	Categorical. Never smoked, former smoker, or current smoker.
TIA	If transient ischemic accident was previously reported in the medical history.	Categorical. Yes or no.
Baseline pharmacological treatments
ACEi	If maintained use of angiotensin-converting enzyme inhibitors was previously reported in the medical history.	Categorical. Yes or no.
Acenocoumarol	If maintained use of acenocoumarol was previously reported in the medical history.	Categorical. Yes or no.
ARB	If maintained use of angiotensin receptor blockers was previously reported in the medical history.	Categorical. Yes or no.
Aspirin	If maintained use of aspirin was previously reported in the medical history.	Categorical. Yes or no.
Direct anticoagulants	If maintained use of direct anticoagulants was previously reported in the medical history.	Categorical. Yes or no.
DPP4i	If maintained use of dipeptidyl peptidase-4 inhibitors was previously reported in the medical history.	Categorical. Yes or no.
Inhaled corticosteroids	If maintained use of inhaled corticosteroids was previously reported in the medical history.	Categorical. Yes or no.
Insulin	If maintained use of insulin was previously reported in the medical history.	Categorical. Yes or no.
LMWH	If maintained use of low-molecular-weight heparin was previously reported in the medical history.	Categorical. Yes or no.
Metformin	If maintained use of metformin was previously reported in the medical history.	Categorical. Yes or no.
Monoclonal antibodies	If maintained use of monoclonal antibodies was previously reported in the medical history.	Categorical. Yes or no.
SGLT2i	If maintained use of sodium-glucose transporter (SGLT) 2 inhibitors was previously reported in the medical history.	Categorical. Yes or no.
Statins	If maintained use of statins was previously reported in the medical history.	Categorical. Yes or no.
Systemic corticosteroids	If maintained use of systemic corticosteroids was previously reported in the medical history.	Categorical. Yes or no.
COVID-19-related variables
General variables
Origin of infection	Suspected site of infection.	Categorical. Community, healthcare staff, or others.
Duration of symptoms	Days since onset of symptoms until admission.	Numerical. Days.
Clinical manifestations
Abdominal pain	If abdominal pain was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Ageusia	If ageusia was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Anosmia	If anosmia was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Anorexia	If anorexia was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Asthenia	If asthenia was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Cough	If cough was present at admission or during the days before according to the medical history.	Categorical. No cough, dry cough, or wet cough.
Diarrhea	If diarrhea was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Dyspnea	If dyspnea was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Headache	If headache was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Myalgia	If myalgia was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Nausea	If nausea was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Odynophagia	If odynophagia was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Vomiting	If vomiting was present at admission or during the days before according to the medical history.	Categorical. Yes or no.
Physical examination at admission
Baseline O2 saturation	Oxygen saturation, in percentage, at hospital admission, without supplementary oxygen therapy.	Continuous. Numerical.
Baseline O2 saturation < 93%	If oxygen saturation without supplementary oxygen at hospital admission was less than 93%.	Categorical. Yes or no.
Confusion	If confusion was present at admission or during the days before, according to the medical history.	Categorical. Yes or no.
Crackles	If crackles were present at admission.	Categorical. Yes or no.
DBP	Diastolic blood pressure, in millimeters of mercury, at hospital admission.	Continuous. Numerical.
Heart rate	Heart rate, in beats per minute, at hospital admission.	Continuous. Numerical.
SBP	Systolic blood pressure, in millimeters of mercury, at hospital admission.	Continuous. Numerical.
Tachypnea	If tachypnea, defined as breathing rate greater than 22 breaths per minute, was present at admission according to the medical history.	Categorical. Yes or no.
Rhonchi	If rhonchi were present at hospital admission.	Categorical. Yes or no.
Temperature	Temperature, in degrees Celsius, at hospital admission.	Continuous. Numerical.
Temperature ≥ 38 °C	If temperature at hospital admission was greater than 38 °C.	Categorical. Yes or no.
Wheezing	If wheezing was present at hospital admission.	Categorical. Yes or no.
Radiological findings
Alveolar condensation	Alveolar condensation in the plain chest radiograph at admission.	Categorical. Absent, unilateral, or bilateral.
Interstitial infiltrate	Interstitial infiltrate in the plain chest radiograph at admission.	Categorical. Absent, unilateral, or bilateral.
Pleural effusion	Pleural effusion in the plain chest radiograph at admission.	Categorical. Absent, unilateral, or bilateral.
Analytical findings
Albumin	Value of serum albumin at admission in g/dL.	Continuous. Numerical.
Creatinine	Value of plasma creatinine at admission in mg/dL.	Continuous. Numerical.
CRP	Value of C-reactive protein at admission in mg/L.	Continuous. Numerical.
Glucose	Value of plasma glucose at admission in mg/dL.	Continuous. Numerical.
Leukocytes	Number of leukocytes’ 106 per liter at hospital admission.	Continuous. Numerical.
Hemoglobin	Value of hemoglobin at admission in g/dL.	Continuous. Numerical.
Lymphocytes	Number of lymphocytes’ 106 per liter at hospital admission.	Continuous. Numerical.
Neutrophils	Number of neutrophils’ 106 per liter at hospital admission.	Continuous. Numerical.
Platelets	Number of platelets’ 106 per liter in blood test at hospital admission.	Continuous. Numerical.
Plasma sodium	Value of plasma sodium at admission in mEq/L.	Continuous. Numerical.
Plasma potassium	Value of plasma potassium at admission in mEq/L.	Continuous. Numerical.
Outcomes
In-hospital mortality	If the patient died during hospitalization due to SARS-CoV-2 infection, or 30 days after hospital discharge.	Categorical. Yes or no.
Length of stay	More or less than 14 days.	Categorical. Yes or no.
Need for NIMV	If during hospitalization the patient has received continuous positive airway pressure (CPAP) and/or bilevel positive airway pressure (BiPAP) and/or high-flow cannula oxygen therapy.	Categorical. Yes or no.
ICU admission	If the patient has required admission to the intensive care unit.	Categorical. Yes or no.