More than a dozen CHPR faculty and fellows have been producing impactful research on opioid use and addiction over the last seven years.


Recent Highlights

Dr. Henry was awarded an NIH R01 grant in October 2017 to develop validated, patient-level risk prediction models for opioid-related overdose by linking statewide prescription, inpatient, and death certificate data in California. He and his team of CHPR research staffers are partnering with the California Departments of Justice, Health Care Services, and Public Health to produce a clinical risk prediction model to incorporate into California’s Prescription Drug Monitoring Program (PDMP) and thus inform prescribing decisions at the point of care. Results from California are expected to be generalizable to the 48 other states that have PDMPs. Ultimately, this project advances a PDPM research program aimed at developing and evaluating tools that clinicians can use to make safer opioid prescribing decisions, and that researchers and policymakers can use to design and evaluate interventions.

Results from Dr. Henry's NIH-funded research into patient experiences with opioid tapering informed a national opioid prescribing guideline: the HHS Guide for Clinicians on the Appropriate Dosage Reduction or Discontinuation of Long-Term Opioid Analgesics. Dr. Henry’s research filled knowledge gaps about patient experiences with opioid tapering in primary care. Dr. Henry and his CHPR team identified critical communication strategies for physicians to use to achieve productive, patient-centered discussions of opioid tapering. The clinical recommendations were published in the official journal of the American Pain Society. These communication strategies were used to design a stories-based opioid tapering intervention that will be tested in a future clinical trial.

A team of CHPR faculty and staff (Drs. Fenton, Agnoli, Xing, Tancredi, Jerant, and Magnan) found a significant increase in rapid opioid tapering between 2008 (12.7%) and 2017 (23.1%) among patients with commercial and Medicare Advantage insurance who were using long-term opioids. This research team, led by Dr. Fenton and Dr. Agnoli in collaboration with partners at Optum Labs, developed an algorithm for identifying opioid dose reduction among these long-term users using pharmacy claims. Tapering was significantly more likely among women and patients with higher baseline opioid doses, and 26.5% of patients undergoing tapering had a maximum dose reduction rate exceeding 10% per week, which exceeds current recommended tapering guidelines for long-term opioid users. Initial results were published in JAMA Network Open, and other findings are being prepared for publication. Future work by this research team will examine racial/ethnic and gender disparities in opioid tapering. The team is now developing a quality indicator of safe opioid dose tapering. 

Other substance use research, conducted by members of the UC Davis Department of Family and Community Medicine research group who are affiliated with CHPR (Drs. Jerant, Franks, Melnikow, and Agnoli), has examined key factors related to prescription opioids and opioid risks. These include studies examining: encounter-level factors associated with opioid dose increases during a patient’s first year of opioid therapy for chronic pain, dose escalation during the first year of longā€term opioid therapy for chronic pain, gender differences in prescribed opioids, satisfaction with care among opioid-prescribed patients, cancer screening among women on opioids, the relationship between opioid prescriptions and physical and mental health, and the association between prescription opioids and short-term mortality. Each of these studies offered new insight into the complex risks and benefits associated with prescription opioids.

A consensus panel report on challenges with implementing CDC opioid guidelines co-authored by CHPR faculty member, Dr. Richard Kravitz, was published in Pain Medicine. The panel identified challenges that included issues with application of dosage ceilings and prescription duration guidance, failure to appreciate the importance of patient involvement in decisions to taper or discontinue opioids, barriers to diagnosis and treatment of opioid use disorder, and lack of access to recommended comprehensive, multimodal pain care. The target audiences for the guidelines include leaders of regulatory agencies, legislators, public and private payers, and healthcare systems.

CHPR faculty member Dr. Aimee Moulin, a UC Davis emergency medicine physician, is working with CHPR to conduct an evaluation of an emergency department treatment referral program for patients with substance use disorders. Dr. Moulin successfully advocated for California State funding to support this intervention as a large-scale pilot program

Medicaid Patient Review and Restriction (MPRR) programs limit the number of prescribers and/or pharmacies that an enrollee can use to obtain prescription opioids. A CHPR research team created a microsimulation model to project the costs and outcomes of MPRR programs. The model supports interactive features that allow users to customize the population demographics and program enrollment criteria and thereby compare projected outcomes and costs of specified policies within a Medicaid cohort. The computer model generated by this project is a tangible tool that can be used by policymakers and stakeholders to ascertain the cost and health impacts of MPRR policies.