Characteristics and outcomes of ICU patients without COVID-19 infection-pandemic versus nonpandemic times: a population-based cohort study

Importance — Outcomes for critically ill COVID-19 are well described; however, the impact of the pandemic on critically ill patients without COVID-19 infection is less clear.

Objectives — To demonstrate the characteristics and outcomes of non-COVID patients admitted to an ICU during the pandemic, compared with the previous year.

Design — A population-based study conducted using linked health administrative data comparing a cohort from March 1, 2020, to June 30, 2020 (pandemic) to a cohort from March 1, 2019, to June 30, 2019 (nonpandemic).

Setting and Participants — Adult patients (18 yr old) admitted to an ICU in Ontario, Canada, without a diagnosis of COVID-19 during the pandemic and nonpandemic periods.

Main Outcomes and Measures — The primary outcome was all-cause in-hospital mortality. Secondary outcomes included hospital and ICU length of stay, discharge disposition, and receipt of resource intensive procedures (e.g., extracorporeal membrane oxygenation, mechanical ventilation, renal replacement therapy, bronchoscopy, feeding tube insertion, and cardiac device insertion). We identified 32,486 patients in the pandemic cohort and 41,128 in the nonpandemic cohort. Age, sex, and markers of disease severity were similar. Fewer patients in the pandemic cohort were from long-term care facilities and had fewer cardiovascular comorbidities. There was an increase in all-cause in-hospital mortality among the pandemic cohort (13.5% vs 12.5%; p < 0.001) representing a relative increase of 7.9% (adjusted odds ratio, 1.10; 95% CI, 1.05–1.56). Patients in the pandemic cohort admitted with chronic obstructive pulmonary disease exacerbation had an increase in all-cause mortality (17.0% vs 13.2%; p = 0.013), a relative increase of 29%. Mortality among recent immigrants was higher in the pandemic cohort compared with the nonpandemic cohort (13.0% vs 11.4%; p = 0.038), a relative increase of 14%. Length of stay and receipt of intensive procedures were similar.

Conclusions and Relevance — We found a modest increase in mortality among non-COVID ICU patients during the pandemic compared with a nonpandemic cohort. Future pandemic responses should consider the impact of the pandemic on all patients to preserve quality of care.