Acute Pain Service Utilization as a Lens on Inequities in Trauma and Inpatient Management

<b>Background:</b> Inequities in pain management are well documented in chronic pain and outpatient settings, yet little is known about disparities in inpatient Acute Pain Service (APS) care. This study evaluated demographic, clinical, and social factors associated with APS utilization and outcomes in an urban safety-net hospital, with a subgroup analysis of trauma patients who presented with at least three rib fractures. <b>Methods:</b> We performed a retrospective cohort study of two patient populations from our institution: (1) all patients receiving APS consultation from 1 January 2020 to 1 November 2022 (<i>n</i> = 1445) and (2) all patients with traumatic rib fractures during this time, stratified by APS consult status (<i>n</i> = 650). Demographics, insurance, comorbidities, opioid prescribing, and discharge outcomes were analyzed using descriptive statistics, multivariable logistic regression, and log-linear models. As APS consultation criteria were not standardized during the study period, referral patterns reflected routine clinical practice rather than predefined eligibility criteria. <b>Results:</b> Across the full APS cohort, patients were disproportionately represented from vulnerable groups: 30.5% were Black, 81.0% had public insurance, and 32.9% had a substance use disorder (SUD). Methadone use was a strong predictor of non-home discharge, including discharges to a medical facility, hospice, or against medical advice (AMA). In the rib fracture cohort, patients receiving APS consults had significantly higher injury severity scores (Injury Severity Score 17.1 vs. 13.0, <i>p</i> < 0.001). Black patients were less likely to receive APS consult (17.3% vs. 28.8%, <i>p</i> = 0.024). However, this association appeared to be attributable to the younger age and male predominance within this subgroup, as both factors were identified as significant predictors of APS consultation. <b>Conclusions</b>: APS utilization at a high-volume safety-net hospital highlights the intersection of medical vulnerability and structural inequities, with greater involvement among patients who were members of racial and ethnic minorities, publicly insured, or diagnosed with SUD. In trauma populations, younger Black men were over-represented, reinforcing the heightened injury risks Black men may face and the downstream effects on patient care. Taken together, these results highlight how APS involvement acts not only as a marker of increased injury severity but also as an intervention to improve care for vulnerable patient populations. As APS teams regularly serve these populations, they are well-positioned to bridge broader gaps through the integration of addiction and social support services, individualized pain management, and seamless coordination of care across specialties. These findings underscore the need for standardized consultation criteria and integration of social and addiction medicine resources into APS care models.