Epidemiology of Substance-Related Admissions to ICUs in the United States

Objectives: To determine the prevalence, demographic characteristics, and predictors of in-hospital mortality for substance-related ICU admissions in the United States. Design: Multicenter, retrospective cohort study. Setting: U.S. ICUs reporting data to the nationally representative Premier Healthcare Database between 2016 and 2019. Patients: Adult ICU admissions with an International Classification of Diseases , 10th Revision diagnosis of a substance-related disorder not in remission. Interventions: None. Measurements and Main Results: Among 4,740,799 ICU admissions, a substance-related diagnosis was present in 760,153 (mean age 51.8 yr, 65.5% male, 73.7% White, 74.5% non-Hispanic), representing 16.0% (95% CI, 16.00–16.07%) of all ICU admissions or approximately one of every six ICU admissions. Alcohol was the most common substance associated with ICU admission (8.9% of all encounters; 95% CI, 8.87–8.92%), followed by opioids and stimulants (4.0%; 95% CI, 3.97–4.01% and 2.9%; 95% CI, 2.91–2.94%, respectively). Rates of nearly all substance-related ICU admissions were higher in patients 55–64 years old and in patients who identified as male, non-Hispanic, and “Other” race (not identified as White, Black, or Asian). In comparing White and Black patients, the two largest racial groups within our cohort, opioid-related ICU admission rates were higher in White patients while stimulant-related ICU admission rates were higher in Black patients. Only 6.5% (95% CI, 6.37–6.60%) of opioid-related ICU admissions identified heroin use. In multivariable analysis adjusting for relevant covariates, odds of in-hospital mortality following a substance-related ICU admission were higher for encounters that included alcohol-related diagnoses (adjusted odds ratio aOR, 1.12; 95% CI, 1.06–1.19), female sex (aOR, 1.07; 95% CI, 1.04–1.09), and non-Hispanic ethnicity (aOR, 1.08; 95% CI, 1.01–1.16). Conclusions: A substantial burden of substance-related diagnoses exists in patients admitted to ICUs. Alcohol use was most common and associated with increased hospital mortality relative to other substances. Rates of substance-related ICU admission differed by age, sex, race, and ethnicity. These findings may have implications for effective allocation of resources toward addiction-related diagnoses, treatment, and secondary prevention for ICU patients.