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Analysis of Emergency Department Encounters Among High Users of Health Care and Social Service Systems Before and During the COVID-19 Pandemic

Educational Objective
To identify the key insights or developments described in this article
1 Credit CME
Key Points

Question  Did emergency department (ED) use decrease among the top 5% of high users of health care and social services in San Francisco County during the COVID-19 pandemic?

Findings  In this cohort study of 8967 individuals, the rate of ED visits decreased by approximately 25% during the pandemic compared with nonpandemic years.

Meaning  Factors associated with decreased ED encounters and health outcomes during the COVID-19 pandemic among previously high users are not clear and warrant further investigation.


Importance  Although the general US population had fewer emergency department (ED) visits during the COVID-19 pandemic, patterns of use among high users are unknown.

Objectives  To examine natural trends in ED visits among high users of health and social services during an extended period and assess whether these trends differed during COVID-19.

Design, Setting, and Participants  This retrospective cohort study combined data from 9 unique cohorts, 1 for each fiscal year (July 1 to June 30) from 2012 to 2021, and used mixed-effects, negative binomial regression to model ED visits over time and assess ED use among the top 5% of high users of multiple systems during COVID-19. Data were obtained from the Coordinated Care Management System, a San Francisco Department of Public Health platform that integrates medical and social information with service use.

Exposures  Fiscal year 2020 was defined as the COVID-19 year.

Main Outcomes and Measures  Measured variables were age, gender, language, race and ethnicity, homelessness, insurance status, jail health encounters, mental health and substance use diagnoses, and mortality. The main outcome was annual mean ED visit counts. Incidence rate ratios (IRRs) were used to describe changes in ED visit rates both over time and in COVID-19 vs non–COVID-19 years.

Results  Of the 8967 participants, 3289 (36.7%) identified as White, 3005 (33.5%) as Black, and 1513 (16.9%) as Latinx; and 7932 (88.5%) preferred English. The mean (SD) age was 46.7 (14.2) years, 6071 (67.7%) identified as men, and 7042 (78.5%) had experienced homelessness. A statistically significant decrease was found in annual mean ED visits among high users for every year of follow-up until year 8, with the largest decrease occurring in the first year of follow-up (IRR, 0.41; 95% CI, 0.40-0.43). However, during the pandemic, ED visits decreased 25% beyond the mean reduction seen in prepandemic years (IRR, 0.75; 95% CI, 0.72-0.79).

Conclusions and Relevance  In this study, multiple cohorts of the top 5% of high users of multiple health care systems in San Francisco had sustained annual decreases in ED visits from 2012 to 2021, with significantly greater decreases during COVID-19. Further research is needed to elucidate pandemic-specific factors associated with these findings and understand how this change in use was associated with health outcomes.

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Article Information

Accepted for Publication: September 13, 2022.

Published: October 28, 2022. doi:10.1001/jamanetworkopen.2022.39076

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2022 Molina M et al. JAMA Network Open.

Corresponding Author: Melanie Molina, MD, Philip R. Lee Institute for Health Policy Studies, Mission Bay Campus Valley Tower, 490 Illinois St, 7th Floor, Box 7118, San Francisco, CA 94158 (melanie.molina@ucsf.edu).

Author Contributions: Ms Evans and Dr Graham-Squire had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Molina, Evans, Montoy, Cawley, Graham-Squire, Kanzaria.

Acquisition, analysis, or interpretation of data: Molina, Evans, Cawley, Graham-Squire, Perez, Raven, Kanzaria.

Drafting of the manuscript: Molina, Evans, Graham-Squire, Perez, Kanzaria.

Critical revision of the manuscript for important intellectual content: Molina, Evans, Montoy, Cawley, Graham-Squire, Raven, Kanzaria.

Statistical analysis: Molina, Evans, Graham-Squire.

Administrative, technical, or material support: Perez, Kanzaria.

Supervision: Montoy, Raven, Kanzaria.

Conflict of Interest Disclosures: Dr Kanzaria reported receiving personal fees and working as a consultant for Amae Health Inc outside the submitted work. Dr Raven’s and Dr Kanzaria’s salaries were supported by a grant from the Benioff Homelessness and Housing Initiative at the University of California, San Francisco. No other disclosures were reported.

Meeting Presentation: Presented at the Society for Academic Emergency Medicine Annual Meeting; May 13, 2022; New Orleans, Louisiana.

Additional Contributions: Margot Kushel, MD, and Charles McCulloch, PhD, contributed uncompensated methodological and statistical expertise, respectively. The San Francisco Department of Public Health, Benioff Homelessness and Housing Initiative, and National Clinical Scholars Program provided data and statistician support as well as mentorship.

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