A recent study has found that California’s CA Bridge program has expanded opioid use disorder treatment services to more than 80% of the state’s emergency departments. Between July 2022 and December 2023, the program reached over 165,000 patients and provided nearly 45,000 instances of buprenorphine treatment. The findings suggest that with appropriate funding, training, and patient navigation support, emergency departments can serve as a key entry point for addiction care.
The opioid crisis remains a major public health issue in the United States. Emergency departments often treat many people with opioid use disorder, but most health systems do not provide evidence-based addiction care. Nationally, only between 5.7% and 11.5% of emergency department patients with opioid use disorder receive medications like buprenorphine, which are proven to reduce overdose deaths and improve outcomes. CA Bridge is currently the largest state-based emergency department addiction treatment initiative in the country.
Researchers examined data from 252 hospitals participating in CA Bridge from July 2022 through December 2023. Each hospital received $120,000 in funding along with technical assistance and training to hire patient navigators and establish addiction treatment pathways. Data sources included grant reports and California’s controlled substances prescribing database.
Key results from June 2022 through December 2023 show that patient navigators engaged individuals with opioid use disorders during more than 165,671 emergency department visits at participating hospitals. Patient engagement rates at public hospitals were about 80% higher than those at private hospitals; provision of buprenorphine was about 50% higher at public hospitals compared to private ones.
In all California emergency departments during 2022, there were over 119,000 people who received a prescription for buprenorphine for opioid use disorder; just over four percent of these prescriptions came from an emergency medicine clinician. Among first-time recipients of buprenorphine prescriptions (58,399 people), around five percent were started by emergency clinicians. Nearly one-fifth of prescribers were new to prescribing this medication. About one-third of patients who received buprenorphine in the emergency department had a follow-up prescription within forty days.
The authors note that while CA Bridge shows promise for transforming emergency departments into effective sites for initiating addiction treatment and linking patients to ongoing care, continued success will depend on sustainable financing and standardized quality measures across institutions. They recommend further research into best practices among high-performing sites and suggest exploring similar models for other substance use disorders such as methamphetamine or alcohol.
“CA Bridge has helped transform emergency care throughout California to include low-barrier buprenorphine for opioid use disorder. The program has developed a successful model for scaling ED addiction care across diverse practice settings, with high adoption and services provision,” said , lead author of the study and researcher at UCLA. “EDs are a strategic point of entry into the addiction care system, and our findings demonstrate that with technical assistance, training, and funding, adoption and services provision are high.”
The study appears in Health Affairs’ September 2025 issue on “Insights About the Opioid Crisis.” The research team includes members from UCLA as well as several public health organizations.
Funding was provided by several entities including the California Department of Health Care Services and the Public Health Institute; $40 million was allocated from state funds—$36 million distributed directly to hospitals—with remaining funds used for administration.
