Comparing the first and second waves of COVID-19 in a tertiary university hospital in Barcelona

<p><strong>Objectives</strong></p> <p>To compare the flow of COVID-19 patients in emergency rooms and hospital wards between the pandemic; first and second waves; at the University Hospital of Vall d'Hebron (Barcelona, Spain), and to compare the profiles, severity and mortality of COVID-19 patients between the two waves.</p> <p><strong>Methods</strong></p> <p>Retrospective observational analysis of COVID-19 patients attending the hospital from February 24 to April 26, 2020 (first wave) and from July 24, 2020, to May 18, 2021 (second wave). We analysed the data of the Electronic Medical Records on patient demographics, comorbidity, severity and mortality.</p> <p><strong>Results</strong></p> <p>The daily number of COVID-19 patients entering the ER dropped by 65% during the second wave compared to the first wave. During the second wave, patients entering the ER were significantly younger (61 vs 63 y.o. p&lt;0.001) and less severely affected (39% vs 48% with a triage level of resuscitation or emergency; p&lt;0.001). ER mortality declined during the second wave (1% vs 2%; p&lt;0.000). The daily number of hospitalised COVID-19 patients dropped by 75% during the second wave. Those hospitalised during the second wave were more severely affected (20% vs. 10%; p&lt;0.001) and were derived to the intensive care unit (ICU) more frequently (21% vs 15%; p&lt;0.001). Inpatient mortality showed no significant difference between the two waves.</p> <p><strong>Conclusions</strong></p> <p>Changes in the flow, severity and mortality of COVID-19 patients entering this tertiary hospital during the two waves may reflect a better adaptation of the health system and the improvement of knowledge on the disease.</p>