(79) Inpatient OUD Management: Associations with PDD, Readmission, and Mortality

Background & Introduction: Hospitalization is thought to be a crucial window of opportunity to intervene on unstable opioid use disorder (OUD)(1), and the inpatient use of medications for opioid use disorder (MOUD) is associated with reduced patient-directed discharge (PDD) and readmissions(2). Management strategies used in the prior prescription opioid and heroin waves have become less effective in the current fentanyl crisis. To counter this, strategies such as more aggressive inpatient up-titration of methadone(3) and novel buprenorphine induction and maintenance regimens(4) have been recently reported.

Existing literature suggests that long-term outpatient treatment with MOUD is associated with a 53% reduction in the risk of all-cause mortality(5). However, there is no data to our knowledge specifically demonstrating the effect of inpatient MOUD on post-discharge mortality. Moreover, prior research has shown that PDD rates can be markedly reduced using inpatient MOUD, but the most effective strategies of inpatient MOUD usage have not been fully identified.

We built a large database of abstracted chart information for patients with history of OUD admitted to Hartford Hospital in Hartford, Connecticut during 2023 and assessed differences in PDD rate, 30- and 90-day readmission rate, and 30- and 90-day post discharge mortality rate based on different OUD management strategies.

Methods: We identified inpatient encounters from 2023 in which the patient may have OUD, using the specific diagnosis “opioid use disorder” as well as nonspecific diagnoses such as “polysubstance use disorder”. Charts were manually reviewed to determine if the patient likely met DSM-5 criteria for OUD. Patients with OUD in long-term treatment-free remission were excluded.

Data were manually abstracted from each encounter including demographics, hospital course details, OUD management strategy, urine drug screen findings, PDD, 30- and 90-day readmission, 30- and 90-day mortality (verified by state mortality data), naloxone prescriptions, and addiction medicine consult service (AMCS) involvement. OUD management strategies were categorized into: MOUD (buprenorphine, methadone, naltrexone), no MOUD offered, patient declined MOUD, disruptions to home MOUD, and uncategorizable. This chart review yielded 1156 encounters, representing 708 unique patients.

We compared PDD, readmission, and mortality for encounters in which patients received MOUD with those in which MOUD was not offered. For this study, the other OUD management strategies were excluded. Encounters during which the patient died were also excluded. We performed subgroup analyses to identify differences between encounters in which patients received methadone versus buprenorphine, and to evaluate if the receipt of methadone taper yielded different outcomes compared to methadone maintenance.

Results: There were significant baseline differences between patients who received MOUD (n=801) and those who were not offered MOUD (n=207). Those who received MOUD were more likely to be female (39.0% vs 26.6%, p< 0.03) and white (53.1% vs 42.0%, p< 0.03). Among patients not offered MOUD, 19.8% were black. Only 9.6% of patients who received MOUD were black. Black patients and men were disproportionately likely to not be offered MOUD (p < 0.03 for each). The AMCS saw 22.2% of the patients who received MOUD, but saw none of the patients who were not offered MOUD.

Patients who received MOUD were less likely to experience PDD (12.1% vs 23.2%, p< 0.03). Readmission rates were similar between the two groups, both at 30 and 90 days. All-cause mortality at 30 days was markedly lower for patients who received MOUD compared to those who were not offered it (1.8% vs 4.4%, p< 0.03). There was a trend towards lower 90 day mortality which did not reach statistical significance (6.0% vs 8.2%, p=0.25). It is not clear if the mortality benefit truly attenuates over time, or if there is not enough power in this study to find a difference.

PDD was higher in patients who received methadone (N=576) compared to those who received buprenorphine (N=225; 14.4% vs 6.2%, p< 0.03). Readmissions at 30 days were lower for patients who received methadone compared to buprenorphine (26.9% vs 34.7%, p< 0.03) but there was no difference at 90 days. There was no significant difference in all-cause mortality between the groups at either 30 or 90 days.

Compared to methadone maintenance (N=527), methadone taper (N=49) was associated with higher rates of PDD (32.7% vs 12.7%, p< 0.03). Readmissions were similar between the groups, both at 30 and 90 days. There was a trend towards higher 30-day all-cause mortality for patients who received tapers (4.1%) compared to maintenance (1.5%) but this did not reach statistical significance (p=0.19). All-cause mortality at 90 days was similar between the taper (4.1%) and maintenance (6.5%) patients with a p-value of 0.51.

Conclusion & Discussion: These data suggest an association between inpatient MOUD and all-cause mortality at 30 days. PDD rates were lower for patients who received MOUD. The demographic differences between patients who received MOUD and those who were not offered MOUD reflect underlying inequities in OUD management. Patients who received MOUD were more likely to be white and female; patients not offered MOUD were more likely to be black and male. Every patient seen by the AMCS was offered MOUD, suggesting that AMCS involvement was associated with reduction of inequity in OUD management.

Our data suggests that use of inpatient methadone tapers rather than maintenance may be associated with high rates of PDD and a trend towards increased 30-day mortality, which calls into question the utility of this intervention.

The retrospective design and demographic differences between the groups render it difficult to assert that there is a causal effect between inpatient MOUD and 30-day all-cause mortality after discharge. Patient factors become challenging to separate from intervention effects. Nevertheless, this study highlights benefits associated with systematically offering MOUD to all hospitalized patients with OUD. Increased utilization of inpatient MOUD will likely reduce PDD, may reduce post-discharge mortality, and will reduce known treatment inequities.

References:

1. Calcaterra, Susan L., et al. "Management of opioid use disorder and associated conditions among hospitalized adults: A Consensus Statement from the Society of Hospital Medicine." Journal of hospital medicine 17.9 (2022): 744-756.

2. Wang, Sijie Jason, et al. "Effect of inpatient medication-assisted therapy on against-medical-advice discharge and readmission rates." The American journal of medicine 133.11 (2020): 1343-1349.

3. Liu, Patricia, et al. "Piloting a Hospital-Based Rapid Methadone Initiation Protocol for Fentanyl." Journal of addiction medicine 18.4 (2024): 458-462.

4. Weimer, Melissa B., et al. "ASAM clinical considerations: buprenorphine treatment of opioid use disorder for individuals using high-potency synthetic opioids." Journal of addiction medicine 17.6 (2023): 632-639.

5. Santo, Thomas, et al. "Association of opioid agonist treatment with all-cause mortality and specific causes of death among people with opioid dependence: a systematic review and meta-analysis." JAMA psychiatry 78.9 (2021): 979-993.