# Reduced need for inpatient care following introduction of long-acting injectable buprenorphine

## TL;DR

Switching to long-acting injectable buprenorphine for opioid use disorder cut inpatient care days and healthcare costs in a real-world study.

## Contribution

Demonstrates significant reduction in inpatient care and costs after adopting long-acting injectable buprenorphine in clinical settings.

## Key findings

- Inpatient care days were reduced by half after switching to LAI buprenorphine.
- Health care costs dropped by ~SEK 45,081 (~USD 4,090) per patient.
- One-year treatment retention was 67%, with 89% overall OAT continuation.

## Abstract

Growing evidence supports long-acting injectable (LAI) buprenorphine in opioid use disorder treatment. Implementation is limited due to concerns about costs as well as potential reduction of support, which could increase strain on health care services. This real-life study follows clinical patients one year prospectively and one year retrospectively from switching from daily sublingual or peroral opioid agonist treatment (OAT) to LAI buprenorphine exploring how this impacts days of inpatient care and emergency room (ER) visits.

From electronic medical records, from four Swedish OAT clinics, we identified all patients (n=128) who had switched from sublingual or peroral OAT, to LAI buprenorphine during the first two years of implementation (2019-2021 in three clinics, 2021–2023 in the fourth). In this within-subject mirror study, patients served as their own controls. The number of days of inpatient care and ER visits were extracted from the electronic medical records using a standard operating procedure. Quasi-Poisson models were used to compare health care utilization before and after starting LAI buprenorphine.

Among the 128 patients, 28 (22%) were female and mean age was 37.8 (SD 9.0) years. Days of inpatient care were reduced by half, dropping from an average of 9.0 to 4.5 days (incidence rate ratio [IRR]: 0.5, 95% CI 0.41–0.61, p<.001), with a health care cost reduction of SEK 45,081 (~USD 4,090) per patient. The decline in days of inpatient care was even steeper among the 85 patients who remained on LAI buprenorphine treatment at 12 months (IRR 0.26, 95% CI 0.20–0.34, p<.001), with a decrease in health care costs of SEK 73,210 (~USD 6,642) per patient. ER visits showed no significant change (IRR: 0.93, 95%CI 0.79 - 1.09). One-year treatment retention to LAI buprenorphine was high (67%). Most patients who discontinued LAI buprenorphine transitioned to other sublingual/peroral forms of OAT, resulting in an overall OAT continuation rate of 89%.

Implementation of LAI buprenorphine in OAT clinical settings was associated with a significant reduction in inpatient care and substantially reduced health care costs. These results challenge common economic hesitations and support wider integration of LAI options in opioid use disorder treatment.

Not applicable.