(36) Impact of Addiction Consult Social Workers on Hospital Readmission Rates

Background & Introduction: Medical hospitalization is a vital opportunity to intervene in the trajectory of substance use disorders (SUDs), as patients with SUDs are frequently readmitted after discharge related to returning to risky substance use. Hospital-based addiction consult teams (ACTs) have demonstrated improved outcomes such as fewer hospital readmissions [1], higher treatment linkage and engagement [2,3], and even reduced mortality [4], especially related to initiation of medications for opioid use disorder. However, little is known about the specific impact of dedicated addiction social work intervention within these interdisciplinary teams. Inpatient addiction medicine consultations can include many activities, including SUD diagnostic assessment, complex withdrawal management, pharmacotherapy initiation, brief psychotherapy like motivational interviewing, harm reduction education, and referral and linkage to resources and various levels of post-hospital addiction treatment. Different combinations of these components can be accomplished by a medical clinician (e.g., physician), a social worker, or both. In this study we sought to explore the impact of social worker involvement on 90-day readmission rates for patients evaluated by the ACT. We hypothesized that patients who received an ACT consultation with social worker involvement would have lower readmission rates when compared to those who received a provider only consultation.

Methods: Data were queried from a centralized addiction medicine dashboard reporting all addiction consultations completed at a safety-net hospital in Denver, Colorado between January 1 and September 30, 2023. Some patients may have had multiple consultations during the study period, each of which was counted separately. Each consultation was dichotomized into Attending-Only vs. Social Work-Involved. Social Work-Involved included patients seen only by ACT SW and those seen by SW and medical provider. Same-institution 90-day readmission rates were calculated for Q1 through Q3 (Jan-Sept) and subdivided by primary SUD (alcohol use disorder [AUD], opioid use disorder [OUD], other). Data will be displayed in table format. The primary intention of reporting these data is descriptive – to be used to generate hypotheses for future analyses. A chi-squared test was performed to assess the null hypothesis that readmission rates are equal in both groups, with statistical significance defined as < 0.05. ACT SW interventions included psychosocial assessment, American Society of Addiction Medicine (ASAM) Level of Care assessment, review of treatment options, transition of care planning, linkage to treatment (both internal and external referrals), collaborative discharge planning with primary medical teams (e.g., related to continuation of methadone at a facility), and coordination with existing outpatient providers.

Results: We identified 1515 completed ACT consultations; 660 primarily for alcohol use disorder, 578 primarily for opioid use disorder, and 277 primarily for other substances or concerns. In total, 90-day readmission rates were 5% lower for patient encounters with ACT SW involvement (p = 0.05), though 90-day readmission rate varied by substance use disorder. Consultations for patients with an OUD that received ACT SW support had 9% lower readmission rate than those seen by an attending alone (p < 0.01). Consultations for patients with an AUD that received ACT SW support did not show a difference in readmission rate than those seen by an attending alone (p=0.73). Consultations for patients with a SUD other than AUD or OUD (primarily stimulant use) had a 5% lower, though non-significant, readmission rate if ACT SW was involved (p < 0.35).

Conclusion & Discussion: Among our sample, consults involving ACT SW resulted in a lower 90-day same-institution readmission rate than those without. This supports the notion that ACT SW intervention may reduce rate of post-hospital destabilization and return to use. This effect was most pronounced for patients with OUD, a disease primarily treated pharmacologically. This may be because our workflow for OUD patients involves both medication induction and ACT SW linkage to medication continuation. This may highlight the multidisciplinary approach needed to treat this disease. ACT SW had the smallest impact on readmission rates for patients with AUD. ACT SW linkage might be expected to have a larger impact on patient outcomes than physician intervention alone considering that medications alone are generally not sufficient in treatment of AUD. This could be explained by limited availability of intensive residential treatment (IRT) beds for publicly insured patients. Our study has limitations. First, patients were not randomized, and thus were subject to selection bias and confounding variables. Second, readmissions were only detected at a single institution. Larger, prospective studies are needed to improve validity. Future hypotheses related to specific SW interventions could be tested in more granular, multi-variable analyses using data not captured in the dashboard.

References:
[1] Raheemullah, Amer & Deng, Huiqiong & Fenno, Lief & Lembke, Anna. (2022). Inpatient Addiction Medicine Consultation on Readmission Rates and Length of Stay. Journal of Addiction and prevention. 10. 10.13188/2330-2178.1000053.

[2] Trowbridge, Paul & Weinstein, Zoe & Kerensky, Todd & Roy, Payel & Regan, Danny & Samet, Jeffrey & Walley, Alexander. (2017). Addiction consultation services – Linking hospitalized patients to outpatient addiction treatment. Journal of Substance Abuse Treatment. 79. 10.1016/j.jsat.2017.05.007.

[3] Englander H, Dobbertin K, Lind BK, Nicolaidis C, Graven P, Dorfman C, Korthuis PT. Inpatient Addiction Medicine Consultation and Post-Hospital Substance Use Disorder Treatment Engagement: a Propensity-Matched Analysis. J Gen Intern Med. 2019 Dec;34(12):2796-2803. doi: 10.1007/s11606-019-05251-9. PMID: 31410816; PMCID: PMC6854181.

[4] Wilson JD, Altieri Dunn SC, Roy P, Joseph E, Klipp S, Liebschutz J. Inpatient Addiction Medicine Consultation Service Impact on Post-discharge Patient Mortality: a Propensity-Matched Analysis. J Gen Intern Med. 2022 Aug;37(10):2521-2525. doi: 10.1007/s11606-021-07362-8. Epub 2022 Jan 25. PMID: 35076857; PMCID: PMC9360378.