ABSTRACT
Introduction: In-hospital delirium is a risk factor for worse critical care outcomes. Alcohol misuse contributes to increased risk of critical illness and greater pneumonia severity. We sought to determine if alcohol misuse was associated with increased risk of critical illness or complications of critical illness including delirium amongst hospitalized COVID-19 patients. Methods: Retrospective study across 12 University of Colorado hospitals (March 2020-April 2021). Adults with a COVID-19 diagnosis were included. Alcohol misuse was defined by validated ICD-10 codes (F10.1∗, F10.2∗, F10.9∗). Multivariable, mixed effects logistic regression models were used to estimate effects of alcohol misuse adjusting for age, sex, body mass index, diabetes and liver disease. Results: We included 6,454 hospitalized COVID-19 patients aged 60 (SD 18 years) with 53% male. Twenty-four percent (n = 1561) required ICU admission, 14.4% (n = 927) endotracheal intubation with a median ICU stay of 6 days [IQR 2 to 15] and duration of mechanical ventilation of 10 days [IQR 5 to 18]. Ten percent of the cohort (n = 644) died in hospital. Delirium was identified in 4% (n = 254) and 257 patients (4%) had alcohol misuse. Patients with misuse were younger (52 vs 60 p < 0.01), men (77 vs 52%, p < 0.01), had more co-morbid liver disease (p-value < 0.01) and received less remdesivir (29 vs 50%, p < 0.01). There was no difference in dexamethasone or vasopressor use. In adjusted analyses, alcohol misuse was associated with 54% increased odds of ICU admission (aOR, 1.54, 95%CI 1.13 to 2.09, p < 0.01) and 46% increased odds of mechanical ventilation (aOR. 1.46, 95% CI 1.03 to 2.08, p < 0.01) compared to patients without misuse. There was a significant interaction between misuse and in-hospital delirium on in-hospital death with odds of death highest amongst patients with both alcohol misuse and identified delirium. Conclusions: Alcohol misuse was associated with increased need for critical care including ICU admission and mechanical ventilation. Delirium was an important modifiable risk factor for worse outcomes in hospitalized patients with alcohol misuse, and the odds of in-hospital death were significantly increased in the presence of bothmisuse and delirium.