IMPORTANCE Research has demonstrated an association between the COVID-19 pandemic and increased alcohol-related liver disease hospitalizations and deaths. However, trends in alcohol-related complications more broadly are unclear, especially among subgroups disproportionately affected by alcohol use.

OBJECTIVE To assess trends in people with high-acuity alcohol-related complications admitted to the emergency department, observation unit, or hospital during the COVID-19 pandemic, focusing on demographic differences.

DESIGN, SETTING, AND PARTICIPANTS This longitudinal interrupted time series cohort study analyzed US national insurance claims data using Optum's deidentified Clinformatics Data Mart database from March 2017 to September 2021, before and after the March 2020 COVID-19 pandemic onset. A rolling cohort of people 15 years and older who had at least 6 months of continuous commercial or Medicare Advantage coverage were included. Subgroups of interest included males and females stratified by age group. Data were analyzed from April 2023 to January 2024.

EXPOSURE COVID-19 pandemic environment from March 2020 to September 2021.

MAIN OUTCOMES AND MEASURES Differences between monthly rates vs predicted rates of high-acuity alcohol-related complication episodes, determined using claims-based algorithms and alcohol-specific diagnosis codes. The secondary outcome was the subset of complication episodes due to alcohol-related liver disease.

RESULTS Rates of high-acuity alcohol-related complications were statistically higher than expected in 4 of 18 pandemic months after March 2020 (range of absolute and relative increases: 0.4-0.8 episodes per 100 000 people and 8.3%-19.4%, respectively). Women aged 40 to 64 years experienced statistically significant increases in 10 of 18 pandemic months (range of absolute and relative increases: 1.3-2.1 episodes per 100 000 people and 33.3%-56.0%, respectively). In this same population, rates of complication episodes due to alcohol-related liver disease increased above expected in 16 of 18 pandemic months (range of absolute and relative increases: 0.8-2.1 episodes per 100 000 people and 34.1%-94.7%, respectively).

CONCLUSIONS AND RELEVANCE In this cohort study of a national, commercially insured population, high-acuity alcohol-related complication episodes increased beyond what was expected in 4 of 18 COVID-19 pandemic months. Women aged 40 to 64 years experienced 33.3% to 56.0% increases in complication episodes in 10 of 18 pandemic months, a pattern associated with large and sustained increases in high-acuity alcohol-related liver disease complications. Findings underscore the need for increased attention to alcohol use disorder risk factors, alcohol use patterns, alcohol-related health effects, and alcohol regulations and policies, especially among women aged 40 to 64 years.