Epidemiology and Outcomes of Previously Healthy Adults among Critically Ill Patients with Covid-19

ABSTRACT

INTRODUCTION: The adverse impact of comorbid conditions on the development of severe illness and risk of death among hospitalized patients with COVID-19 has been well-documented. However, the population-level epidemiology and outcomes of previously healthy [PH] adults compared to those with prior comorbidities [PC] among COVID-19 patients requiring ICU admission are unknown. METHOD(S) We used a statewide dataset to identify hospitalizations aged >=18 years with ICU admission and a diagnosis of COVID-19 in Texas during April 1-December 31, 2020. COVID-19 was defined by ICD-10 code U07.1. PH was defined as absence of the comorbidities included in the Charlson Comorbidity Index, and of obesity, malnutrition, mental disorders, and substance and alcohol use disorders. A hierarchical, mixed-effects model was fit to estimate the association of PH with short-term mortality (defined as in-hospital death or discharge to hospice) among ICU admissions. A similar approach was used to identify predictors of short-term mortality among the PH group. RESULT(S) Among 58,845 ICU admissions with COVID-19, 6,760 (11.6%) were PH. Compared to those with PC, those with PH were younger (aged >=65 years 36.1% vs 49.4%), more commonly racial/ethnic minority (63.8% vs 61.5%), and with lower mean [SD] number of organ dysfunctions (1.2 [1.1] vs 1.8 [1.4]) [p< 0.001 for all comparisons]. Short-term mortality was lower among PH than among PC (16.4% vs 25.0%). However, following adjustment for confounders, the risk of short-term mortality was higher among PH (adjusted odds ratio [aOR] 1.37 [95% CI 1.25-1.51]). Among PH ICU admissions, short-term mortality increased with age ([aOR] 35.20 [95% CI 22.09-56.09];>=65 vs 18-44 years) and management at facilities with >=50 ICU beds ([aOR] 4.43 [95% CI 1.07-18.32] vs < 10 ICU beds). CONCLUSION(S) PH was uncommon among critically ill adults with COVID-19 and PH patients had substantially lower short-term mortality than those with PC. However, once risk-adjusted, the odds of short-term mortality were, unexpectedly, 37% higher among PH, with the latter facing higher risk of death when managed at hospitals with higher number of ICU beds. Additional studies are needed to identify the patient-, care process-, and health system-related contributors to these findings.