Understanding the association between frequent emergency department use and jail incarceration: A cross-sectional analysis

Background: Frequent emergency department (ED) use and incarceration can be driven by underlying structural factors and social needs. If frequent ED users are at increased risk for incarceration, ED-based interventions could be developed to mitigate this risk. The objective of this study was to determine whether frequent ED use is associated with incarceration. Methods: We conducted a retrospective cross-sectional study of 46,752 individuals in San Francisco Department of Public Health's interagency, integrated Coordinated Care Management System (CCMS) during fiscal year 2018–2019. The primary exposure was frequency of ED visits, and the primary outcome was presence of any county jail incarceration during the study period. We performed descriptive and multivariable analysis to determine the association between the frequency of ED use and jail encounters. Results: The percentage of those with at least one episode of incarceration during the study period increased with increasing ED visit frequency. Unadjusted odds of incarceration increased with ED use frequency: odds ratio (OR) = 2.14 (95% confidence interval [CI] = 1.94–2.35) for infrequent use, OR = 4.98 (95% CI = 4.43–5.60) for those with frequent ED use, and OR = 12.33 (95% CI = 9.59–15.86) for those with super-frequent ED use. After adjustment for observable confounders, the odds of incarceration for those with super-frequent ED use remained elevated at 2.57 (95% CI = 1.94–3.41). Of those with super-frequent ED use and at least one jail encounter, 18% were seen in an ED within 30 days after release from jail and 25% were seen in an ED within 30 days prior to arrest. Conclusions: Frequent ED use is independently associated with incarceration. The ED may be a site for intervention to prevent incarceration among frequent ED users by addressing unmet social needs.