Measured using patient records at a single timepoint: 1. COVID-19 incidence 2. COVID-19 severity (COVID-19 severity classification: 1) SpO2 < 95% on room air at sea level; 2) vigorous breathing effort; 3) cyanosis; 4) severe pneumonia; 5) Severe Acute Respiratory Syndrome (SARS); 6) sepsis; 7) septic shock)

Measured using patient records at a single timepoint: 1. COVID-19 incidence 2. COVID-19 severity (COVID-19 severity classification: 1) SpO2 < 95% on room air at sea level; 2) vigorous breathing effort; 3) cyanosis; 4) severe pneumonia; 5) Severe Acute Respiratory Syndrome (SARS); 6) sepsis; 7) septic shock)