A More Accurate Measurement of COVID-19 Hospitalizations

COVID-19 hospitalizations are a key indicator of the SARS-CoV-2 pandemic. The US Centers for Disease Prevention and Control describes oxygen supplementation as a measure of severe disease. SARS-CoV-2 PCR positive patients hospitalized without hypoxia or requiring oxygen may have been identified incidentally due to routine screening practices. We describe the application of a revised case definition for COVID-19 hospitalization based on the case-patient oxygen requirement on admission. Using data collected from consecutive SARS-CoV-2 PCR positive hospital admissions in December 2021 and January 2022 at a large safety net hospital in Los Angeles County, we highlight differences between patients hospitalized with COVID-19 (i.e., no oxygen requirement on admission or `incidental` infection) and those hospitalized for COVID-19 (i.e., oxygen requirement on admission). We conducted multivariable modeling to determine the effect of age as a positive predictor of COVID-19 hospitalization and vaccination or prior infection as a negative predictor. The revised case-definition resulted in a substantial decrease in the number of COVID-19 hospitalizations during the study period: 67.5% of SARS-CoV-2 PCR positive hospital admissions were not for COVID-19 but with COVID-19. A revised case-definition for COVID-19 hospitalization that includes the oxygen requirement on admission is needed to more accurately monitor the pandemic and inform public health policy.