(15) Discharge on MOUD Reduces Relapse in Trauma Patients with Prior Opioid Dependence

Background & Introduction: Patients with opioid use disorder (OUD) are more susceptible to traumatic injury with OUD being a comorbid diagnosis in about 1% of operative trauma cases. While inpatient admission is an opportunity to engage those with OUD and initiate addiction treatment, the diagnosis is often overlooked or inadequately managed among hospitalized patients.

Among trauma patients with OUD, ensuring adequate post-operative pain control while trying to mitigate post-discharge opioid misuse is a frequent challenge as concerns among providers regarding appropriate analgesia are often due to fear of worsening addiction in those with active OUD or causing a relapse in those with OUD in remission. Individuals with OUD may also be engaged on a medication for opioid use disorder (MOUD) such as methadone or buprenorphine-naloxone (bup-nx) prior to admission, which can further complicate management.

The perioperative period is a vulnerable time for these patients, as they often face pain from their injury, exposure to prescription opioids, and potentially acute opioid withdrawal. While studies have established the benefits of an addiction consult service (ACS) and improved outcomes when initiating MOUD prior to discharge for hospitalized patients with OUD, no study has examined these interventions with regards to one-year relapse status in surgical trauma patients.

Methods: An urban level-one trauma center’s trauma registry was queried to identify all adult (ages 18+) patients with documented prior diagnosis of OUD admitted to the trauma surgery service between January 1, 2017 and December 31, 2022. Those discharged as deceased and those who continued to use non-prescribed opioids (defined as illegal opioids and/or non-prescribed prescription opioids) during hospitalization were excluded. Demographics, inpatient OUD targeted interventions, and post-hospitalization outcomes were extracted through retrospective chart review.

Study participants were stratified by one-year relapse status, defined based on the DSM-5 definition of sustained remission of OUD, which requires 12 months of abstinence. This was assessed as any documented (either patient reported or positive urine screen) non-prescribed opioid use during this period. Because all participants had discontinued any non-prescribed opioids throughout their hospitalization, patients were considered discharged as abstinent, establishing a uniform baseline. Participants with unknown one-year relapse status were excluded from analysis (n=108).

Chi squared, Fischer’s exact, and Kruskal-Wallis analysis were then conducted, with statistical significance designated by p< 0.05. Two modified Poisson models were used to estimate relative risk and 95% confidence intervals of relapse within one year, with one model including impact of MOUD on admission and the other MOUD at discharge.

Results: Among 341 participants with OUD presenting for traumatic injury from 2017 to 2022, 211 met inclusion criteria. The incidence of relapse in this group at one-year was 60.6%. On average, participants were more likely to be male, white, and government insured. Those who relapsed tended to be younger, were more likely to be injured via violent intent, and had a shorter hospital length of stay (p=0.022, p=0.004, and p=0.012, respectively).

Among those who relapsed, participants were more likely to have last used a non-prescribed opioid within 12 months pre-admission than those who did not relapse (88% vs. 30%, p< 0.0001). Approximately half of participants were admitted to the hospital already taking a prescribed MOUD, and whether participants relapsed or not, they were equally likely to be admitted on an MOUD (51%, p=0.980).

Of the 107 individuals admitted on an MOUD, 98 were continued on an MOUD and 9 were discontinued. Of the 104 either not on an MOUD or with an unknown MOUD status on admission, 33 were initiated on an MOUD and 71 remained not on an MOUD. Of the 131 discharged on an MOUD, there were twice as many individuals discharged on methadone than on bup-nx (84 vs. 42), compared to at admission where more entered on bup-sx than methadone (54 vs. 48). Of those discharged on methadone, relapse rates were 83% compared to 50% on bup-nx (p < 0.0001).

Compared to those who did not relapse, those who relapsed were more likely to be discharged on an MOUD (73% vs. 46%, p< 0.0001) and more likely to have received consults from the ACS (61% vs. 45%, p=0.020). After adjusting for last pre-hospitalization non-prescribed opioid use, violent intent of injury, injury severity score (ISS), and length of stay, however, modeling showed patients discharged on an MOUD had a 34% lower risk of relapse at one year when compared to those without an MOUD at discharge (RR 0.66, 95% CI 0.50 – 0.88). Patients admitted on an MOUD had a 9% higher risk of relapse at one year compared to those not admitted on an MOUD; however, this was not statistically significant (RR 1.09, 95% CI 0.92 – 1.30). There were no statistically significant associations in either model for relapse and presence of the ACS.

Conclusion & Discussion: Analysis showed being discharged on an MOUD reduced relapse rate by 34% in the year following hospitalization. Conversely, being admitted on an MOUD was not protective against relapse. This suggests that focus should be placed on ensuring an MOUD is continued or initiated during hospitalization for trauma patients with OUD.

While there was no statistically significant reduction in relapse with the ACS, this might reflect provider bias, where high-risk patients were preferentially consulted, rather than its lack of effectiveness. Given prior studies have shown the ACS to be effective among hospitalized OUD patients, and since the ACS is typically needed for MOUD initiation, the ACS intervention remains important.

While there was a trend of initiating new MOUD users on methadone and switching bup-nx users to methadone, relapse rates were significantly higher among those discharged on methadone compared to bup-nx. Regardless of reasoning for this preference, further research must explore if bup-nx is a better fit for this population given the 33% difference in relapse rates.

With this study’s small sample size and potential for selection bias due to exclusion of patients with missing relapse data, stronger conclusions are limited; however, the study findings are still an important contribution to the literature in this understudied population.

References: Herscher, M., Fine, M., Navalurkar, R., Hirt, L., & Wang, L. (2020). Diagnosis and management of opioid use disorder in hospitalized patients. Medical Clinics of North America, 104(4), 695–708. https://doi.org/10.1016/j.mcna.2020.03.003

Karamchandani, K., Klick, J. C., Linskey Dougherty, M., Bonavia, A., Allen, S. R., & Carr, Z. J. (2019). Pain management in trauma patients affected by the opioid epidemic: A narrative review. Journal of Trauma and Acute Care Surgery, 87(2), 430–439. https://doi.org/10.1097/ta.0000000000002292

Muller, M., Weyer, G., Zakrison, T., & Ari, M. (2023). Impact of an opioid use disorder consult service on hospitalized trauma patients with opioid use disorder. Journal of Trauma and Acute Care Surgery, 95(2), 226–233. https://doi.org/10.1097/ta.0000000000003965

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