Health system resource use among populations with complex social and behavioral needs in an urban, safety-net health system

Background: Costs incurred by health systems when caring for populations with social or behavioral complexity are poorly understood. We compared the frequency and costs of unreimbursed care among individuals with complexity factors (homelessness, a history of county jail incarceration, and/or substance use disorder or mental illness [SUD/MI]). Methods: We conducted a cross-sectional analysis using electronic health record data for adults aged 18 and older between January 1, 2016 and December 31, 2017 from a Midwestern safety-net health system. Zero-inflated negative binomial regression models were used to assess risk-adjusted associations between complexity factors and care coordination encounters, missed appointments, and excess inpatient days. Results: Our sample included 154,719 unique patients; 6.8% were identified as homeless, 7.8% had a history of county jail incarceration, and 20.6% had SUD/MI. Individuals with complexity factors were more likely to be African-American, Native American, or covered by Medicaid. In adjusted models, homelessness and SUD/MI were significantly associated with care coordination encounters (RR 1.8 [95% CI,1.7-2.0]; RR 1.9 [95% CI,1.8-2.0]), missed appointments (RR 1.5 [95% CI,1.4-1.6]; RR 1.7 [95% CI,1.7-1.8]), and excess inpatient days (RR 1.5 [95% CI,1.3-1.81; RR 2.8 [95% CI,2.5-3.1]). County jail incarceration was associated with a significant increase in missed appointments. In 2017, SUD/MI accounted for 81.8% ($7,773,000/$9,502,000) of excess costs among those with social or behavioral complexity. Conclusions: Social and behavioral complexity are independently associated with high levels of unreimbursed health system resource use.