Background: The extent to which the COVID-19 pandemic has affected outcomes for patients with unplanned hospitalizations is unclear.
Objective: To examine changes in in-hospital mortality for patients without COVID-19 during the first 10 months of the pandemic (March 4, 2020 to December 31, 2020).
Design, setting, and participants: Observational study of adults with unplanned hospitalizations at 51 hospitals across 6 Western states.
Exposures: Unplanned hospitalizations occurring during the spring COVID-19 surge (March 4 to May 13, 2020; Period 1), an intervening period (May 14 to October 19, 2020; Period 2), and the fall COVID-19 surge (October 20 to December 31, 2020; Period 3) were compared with a pre-COVID-19 baseline period from January 1, 2019, to March 3, 2020.
Main outcomes and measures: We examined daily hospital admissions and in-hospital mortality overall and in 30 conditions.
Results: Unplanned hospitalizations declined steeply during Periods 1 and 3 (by 47.5% and 25% compared with baseline, respectively). Although volumes declined, adjusted in-hospital mortality rose from 2.9% in the pre-pandemic period to 3.5% in Period 1 (20.7% relative increase), returning to baseline in Period 2, and rose again to 3.4% in Period 3. Elevated mortality was seen for nearly all conditions studied during the pandemic surge periods.
Conclusion: Pandemic COVID-19 surges were associated with higher rates of in-hospital mortality among patients without COVID-19, suggesting disruptions in care patterns for patients with many common acute and chronic illnesses.