California program successfully scales emergency department addiction treatment statewide

A comprehensive study shows that California's CA Bridge program has successfully implemented opioid use disorder treatment services across more than 80% of the state's emergency departments, reaching over 165,000 patients and providing nearly 45,000 instances of buprenorphine treatment from July 2022 through December 2023 alone. The initiative proves that emergency departments can serve as a critical entry point for addiction care when provided with proper funding, training, and patient navigation support.

Why it matters

The opioid crisis continues to devastate communities across America, with emergency departments treating large numbers of people with opioid use disorder but most health systems failing to provide evidence-based addiction care. Nationally, only 5.7% to 11.5% of emergency department patients with opioid use disorder receive medications for opioid use disorder, life-saving medications that reduce overdose deaths and improve treatment outcomes. CA Bridge represents the largest state-based emergency department addiction treatment initiative in the United States, offering a potential roadmap for nationwide implementation.

What the study did

Researchers analyzed data from 252 California hospitals participating in CA Bridge from July 2022 through December 2023. The program provided hospitals with $120,000 in funding, technical assistance, and training to hire patient navigators, support clinical champions, and establish addiction treatment pathways. Using grant reporting data and California's controlled substances prescribing database, researchers tracked patient navigator encounters, buprenorphine treatments, and subsequent care engagement across rural, urban, public, and private hospitals.

What they found

The program achieved remarkable reach and effectiveness:

• From June 2022 through December 2023 at CA Bridge participating hospitals:
  • Patient navigators engaged patients with opioid use disorders in over 165,671 emergency department visits.
  • Patient engagement at public hospitals was about 80% higher than public hospitals. 
  • Provision of buprenorphine treatment at public hospitals was about 50% higher than private hospitals.
• In 2022, across all California EDs:
  • 119,271 people received a prescription for buprenorphine for treatment of opioid use disorder, of whom 5,150 people (4.3 percent) received that prescription from an emergency medicine clinician.
  • Among the 58,399 people receiving a first-time buprenorphine prescription, 5.3% were started by emergency clinicians.
  • There were 1,737 unique emergency clinician prescribers, with nearly 22% new to prescribing buprenorphine.
  • About 36% of patients who received an buprenorphine prescription in the emergency department had a follow-up prescription within 40 days.
  • Patients received a median 58 days of uninterrupted treatment within one month of receiving a buprenorphine in the emergency department.

What's next

The success of CA Bridge demonstrates that emergency departments can be transformed into effective sites for initiation of addiction treatment and linkage to maintenance care, but researchers emphasize the need for sustainable financing and quality measures to support nationwide dissemination. Future work should focus on understanding implementation strategies used by high-performing sites, developing standardized quality metrics for emergency addiction care, and exploring similar initiatives for other substance use disorders including methamphetamine and alcohol. The program's model could inform national policy discussions about expanding emergency department addiction services.

From the experts

"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 Dr. Elizabeth Samuels, 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."

About the study

"Increasing Emergency Department Patient Navigation and Buprenorphine Use: A Model for Low-Barrier Treatment." The study appears in the Health Affairs September 2025 issue on "Insights About the Opioid Crisis,” which includes the latest empirical research and policy perspectives, available at https://www.healthaffairs.org/opioids.

About the Research Team

Elizabeth A. Samuels (UCLA), Allison D. Rosen (UCLA), Sarah Abusaa (Public Health Institute), Annette M. Dekker (UCLA), David L. Schriger (UCLA), Steven J. Shoptaw (UCLA), Mariah M. Kalmin (RAND Corporation), Chunqing Lin (UCLA), Serena Clayton (Public Health Institute), Sarah Windels (Public Health Institute), Elizabeth Keating (Public Health Institute), Sherrie Cisneros (Public Health Institute), Arianna Campbell (Public Health Institute), Aimee Moulin (Public Health Institute), Andrew A. Herring (Public Health Institute)

Funding and Disclosures

The authors acknowledge grant support from the California Department of Health Care Services, the California Health Care Foundation, the Public Health Institute, and the National Association of County and City Health Officials. The program cost $40 million from the state general budget, with $36 million distributed to hospitals and $4 million for program administration, training, and monitoring. Authors assume full responsibility for the accuracy of ideas presented, which do not represent the views of supporting institutions.