Relationship Between a State-Directed Lockdown on Non-COVID-19-related ICU Admissions and Mortality in a Multicenter Colorado Healthcare System

Design: We performed a retrospective analysis of all medical ICU admissions in the University of Colorado Health System in four predefined periods: 1) prepandemic (2 mo prior to lockdown period 1); 2) mandated lockdown from March 26 to April 26, 2020 (period 2); 3) between surges (period 3); and 4) nonmandated lockdown surge (between November 1, 2020, and March 31, 2021, period 4).

Setting: Nonsurgical ICU admissions at the University of Colorado Health Systems, including 10 hospitals throughout Colorado.

Subjects: All ICU admissions in four predefined time periods.

Measurements And Main Results: We included 13,787 patients who were admitted during the four study periods. The 28-day mortality rates for non-COVID-19 ICU admissions following index ICU admission were 13.6%, 18.0%, 13.5%, and 16.0% across periods 1-4, respectively. However, the increased odds in non-COVID-19 ICU mortality during the mandated lockdown period relative to prepandemic 1 (odds ratio [OR], 1.39; 95% CI, 1.11-1.72; = 0.0.04) was attenuated and nonsignificant after adjustment for demographics, comorbidities, diagnosis flags, and severity (OR, 1.15; 95% CI, 0.89-1.48; = 0.27). Similar results were found in time-to-event analyses. The most common diagnosis in each time period was acute respiratory failure (ARF), and we found it to have increased during lockdown ( < 0.001), whereas sepsis admissions increased during and decreased after lockdown ( = 0.004). Admissions for alcohol withdrawal syndrome (AWS) increased during lockdown and 6 months afterwards ( = 0.005).

Conclusions: For non-COVID-19-related ICU admissions, mortality rate was similar before, during, and after Colorado's month long lockdown after confounder adjustment, including typical ICU admission flags. Primary admission diagnoses shifted throughout the predefined study periods with more admissions for severe critical diagnoses (i.e., ARF, sepsis, AWS) occurring during the mandated lockdown and nonmandated lockdown periods compared with the prepandemic and between surge period. This would suggest that the perceived increase in mortality during the lockdown for non-COVID-19 ICU admissions may be related to a shift inpatient demographics.