Abstract
BackgroundThe early months of the COVID-19 pandemic were fraught with much uncertainty and some resource constraint. We assessed the change in survival to hospital discharge over time for intensive care unit patients with COVID-19 during the first three months of the pandemic and the presence of any surge effects on patient outcomes.MethodsRetrospective cohort study with electronic medical record data of all patients with laboratory-confirmed COVID-19 admitted to intensive care units from February 25, 2020 to May 15, 2020 admitted to intensive care units of 26 hospitals of an integrated delivery system in the Western United States. Patient demographic, comorbidity and severity of illness were measured along with exposure to pharmacologic and medical therapies and hospital outcomes over time. Multivariable logistic regression models were constructed to assess the change in survival to hospital discharge over time during the study period.ResultsOf 620 patients with COVID-19 admitted to the study ICUs (mean age 63.5 years (SD 15.7) and 69% male), 403 (65%) survived to hospital discharge and 217 (35%) died in hospital. Survival to hospital discharge increased over the study period from 60.0% in the first two weeks of patient admission to 67.6% in the last two weeks. In a multivariable logistic regression analysis, the risk-adjusted odds of survival to hospital discharge increased over time (bi-weekly change, adjusted odds ratio [aOR] 1.22, 95%CI 1.04-1.40, P = 0.02). Additionally, an a priori-defined explanatory model showed that after adjusting for both hospital occupancy and COVID positive/PUI percent hospital capacity, and the same set of covariates, the temporal trend in risk-adjusted patient survival to hospital discharge remained the same (bi-weekly change, aOR 1.18, 95% CI 1.00 to 1.38, P = 0.04) and a greater COVID positive/PUI percentage of hospital capacity remained significantly and inversely associated with survival to hospital discharge (aOR 0.95, 95% CI 0.92 to 0.98, P < 0.01).ConclusionsDuring the the early COVID-19 pandemic, risk-adjusted survival to hospital discharge increased over time for critical care patients. This may have been partially explained by surge affects, as measured by a greater COVID positive/PUI percentage of hospital capacity.