2025 annual report
Celebrating the accomplishments and contributions of our scientists, physician researchers, and staff

As we reflect on 2025, we recognize a year marked by both challenge and resilience.
January’s Southern California wildfires deeply affected our research community, displacing many due to evacuations, smoke or other property damage, and even loss of homes. In the midst of hardship, our department came together to support one another and our communities. Many donated goods or volunteered their time. Others used their scientific expertise to study the short- and long-term effects of wildfire, from health care utilization to potential impacts on pregnant mothers and their children.
In the months that followed, our research program, like many others around the country, navigated an uncertain funding environment. Throughout this period, our leadership team, scientists, physician researchers, and staff responded with focus, adaptability, and a shared sense of purpose. Even as our funding mix evolved, we secured new grants and contracts, ending the year on solid financial footing and with significant scientific achievements.
These accomplishments reflect the dedication of our research scientists, physician researchers, and staff. We are grateful for the rigor, collaboration, and commitment each individual and team brings to our department, and for the way our community supports one another while advancing care and discovery.
We extend our sincere thanks to Kim Kaiser, EdD, for her administrative leadership from mid-2021 through 2025, who took on a new role as Chief Administrative Officer for the Downey Medical Center in January 2026. Her steady guidance strengthened our department and expanded our connections with the SCPMG Quality organization. We look forward to working closely with her successor, Julie John, MA, MSN, RN, as we advance research that improves care and health outcomes for Kaiser Permanente members and the communities we serve.
Investigators and staff

Scientists, physicians, and others in Kaiser Permanente Southern California published 772 journal articles in 2025.
Despite a challenging environment, our research teams published the highest number of journal articles in the history of the research program, exceeding the already high numbers recorded during the peak COVID-19 years. Publications covered diverse areas of focus, including cancer, child and adolescent health, cardiometabolic health, infectious disease, mental health, and vaccines. This work spanned the full continuum of care, informing preventive strategies, clinical treatment decisions, and long-term health needs and outcomes.
Research with real-world impact
Our research turns evidence into everyday care and healthier communities. By testing solutions in real-world settings, we remove barriers, improve workflows, and help successful approaches spread across systems.
One example is an in-office hemoglobin A1C testing program for diabetes care. With results available during the visit, clinicians can adjust treatment immediately. A study published January 13, 2025, in the Journal of General Internal Medicine found improved blood sugar levels among patients with poorly controlled diabetes, showing how a simple workflow change can improve outcomes.
We also generate evidence that shapes healthier environments. Over 25 years of parks research, investigators have shown how design and programming support physical activity and well-being. Communities use this evidence to guide investments that help more people move and connect.
In specialty care, clinical trials help patients benefit from new discoveries sooner. At Kaiser Permanente Riverside Medical Center, a retinal research center expands access to studies such as gene therapy and new stem cell delivery techniques. By integrating research into care, we accelerate progress while protecting vision and quality of life.
Many of our published studies identify practical ways to improve outcomes. Examples include reduced dementia risk among older adults who received the shingles vaccine, new insights on opioid tapering and overdose risk, and evidence that physical activity supports postpartum weight loss.
Learn more in 2025 Research Highlights.
Findings that make headlines
Our research program made headlines throughout 2025, with dozens of studies covered by leading national and regional media including the Associated Press, the Los Angeles Times, NPR, and NBC News. This coverage amplified how evidence generated in our care settings informs decisions that affect patients and communities.
Reporters focused on a wide range of topics, from emergency response and virtual care during the Los Angeles wildfires to studies on the protective benefits of the shingles vaccine. Media also covered practice-changing findings on intensive blood pressure control for patients with chronic kidney disease and research on suicide prevention following implementation of the Zero Suicide Model.
Our experts were in the news as well. Physicians and scientists were tapped to interpret new findings and explain what they mean for care delivery. Their voices helped translate complex research into actionable, patient-centered insight, strengthening trust in Kaiser Permanente Southern California as a source of credible health information.
Learn more in Research in the Media.
Publications

New & notable clinical projects
Dedicated programs in our region support clinically relevant research to improve the health of our patients and the communities we serve.

In 2025, the clinical trials team supported more than 430 active clinical trials protocols across 39 therapeutic areas, offering our patients opportunities to participate in research that may shape the future standards of care.
Our clinical trials program connects patients with leading‑edge research, offering opportunities to access potentially life-saving treatments, spanning investigational medications and devices as well as prevention strategies.
Highlighted cancer studies include trials that add targeted therapy to lung cancer immunotherapy, use post-surgery blood tests to guide colon cancer chemotherapy, and test de-escalated regimens that preserve outcomes. Other studies aim to reduce long-term side effects of breast cancer treatment and compare new hormone options for advanced prostate cancer.
Our general medicine portfolio spans multiple therapeutic areas, including studies of new devices and therapies for heart disease, stroke, kidney disease, macular degeneration and high-risk pregnancy. Prevention trials test longer-acting HIV prevention and immune-based acne strategies.
Learn more about our 2025 Selected Clinical Trials.
Embedding research in clinical practice
The Care Improvement Research Team advances research that is embedded in day-to-day clinical practice. Scientists collaborate with frontline clinicians and operational leaders to identify research questions that matter most to patients and health professionals.
Each year, the program funds a small set of projects that are clinically and operationally relevant, with guidance and financial support from the Southern California Permanente Medical Group. Results from CIRT projects help improve care delivery and health outcomes for Kaiser Permanente members.
In 2025, CIRT funded 14 projects.
Learn more about the 2025 CIRT projects.
Engaging physicians in research
The Regional Research Committee serves as a key hub for engaging physicians in research across the region. It supports multiple programs to connect frontline clinicians and operational leaders with clinically relevant research.
Each year, the committee awards funds from Kaiser Permanente’s Community Health program for research projects led by clinicians and other health care professionals in Southern California. These studies tackle practical clinical questions and can help identify more effective ways to prevent and treat common health conditions.
In 2025, the committee awarded funds to support 16 studies in 3 categories: Traditional grants, RRC Ambient AI grants, and RRC-KPSOM Research Program Development grants.
Learn more about the 2025 RRC projects.
Clinical Research Projects

Financial overview
Funding for research at Kaiser Permanente Southern California totaled $94.2 million in 2025.

Despite a challenging environment, our research program continued to attract new funds and ended the year on solid financial footing.
Kaiser Permanente Southern California research funding comes from a variety of external and internal sources.
In 2025, 70% of total funding came from external sources. Of that, 50% came from federal grants and 50% from industry and foundation contracts.
Kaiser Permanente provided the remaining funds, through the Kaiser Permanente Community Health program, the Southern California Permanente Medical Group, and the Garfield Memorial Fund.
There were more than 460 funded research projects in 2025 in Kaiser Permanente Southern California, including new and ongoing studies.
Research funding

Leadership and investigators
Our research program encompasses investigators in 6 scientific divisions. Each division is led by a scientific or physician director. Administrative leadership oversees research support, technical, operational, business, and other teams that support research efforts.

Scientific leadership
Benjamin I. Broder, MD, PhD, interim senior director of research
Huong Q. Nguyen, PhD, RN, interim scientific director, Health Services Research & Implementation Science
Kristi Reynolds, PhD, MPH, scientific director, Epidemiologic Research
William J. Towner, MD, FACP, FIDSA, physician director, Clinical Trials
Bechien U. Wu, MD, MPH, physician director, Clinician Research
Anny H. Xiang, PhD, MS, scientific director, Biostatistics Research
Deborah Rohm Young, PhD, MBA, scientific director, Behavioral Research
Administrative leadership
Kim E. Kaiser, EdD, MHA, administrative leader
Annie Chen, MBA, director of research administration, Shared Services
Hai Linh Kerrigan, PharmD, division research administrator, Clinical Trials Research
Allan Slatkin, division research administrator, Behavioral Research, Biostatistics Research, Clinician Research, Epidemiologic Research, and Health Services Research & Implementation Science
Investigators
Division of Behavioral Health
Scientific director
Deborah Rohm Young, PhD, MBA
2025 research scientists
Deborah A. Cohen, MD, MPH
Corinna Koebnick, PhD, MSc
Claudia Nau, PhD
Sonya Negriff, PhD
Laurel Sarfan, PhD
Division of Biostatistics Research
Scientific director
Anny H. Xiang, PhD, MS
2025 research scientists
Heidi Fischer, PhD
Bing Han, PhD
Lei Qian, PhD
Ernest Shen, PhD
Margo A. Sidell, ScD, MSPH
Jeff Slezak, MS
Stanley Xu, PhD, MS
Hui Zhou, PhD, MS
Division of Clinical Trials Research
Physician director
William J. Towner, MD, FACP, FIDSA, Infectious Diseases, Los Angeles
2025 principal investigators by therapeutic area
Bone Marrow Transplant
Leonardo Torres Farol, MD, Los Angeles
Cardiology
Somjot S. Brar, MD, MPH, Los Angeles
Jeffrey Cavendish, MD, San Diego
Nigel Gupta, MD, Los Angeles
Bahram Khadivi, MD, San Diego
William J. Mosley II, MD, FACC, San Bernardino County
Jonathan Neyer, MD, Los Angeles
Colorectal Surgery
Daniel Klaristenfeld, MD, San Diego
Endocrinology
Patricia Wu, MD, San Diego
Gastroenterology
Gareth S. Dulai, MD, Downey
Bechien U. Wu, MD, MPH, Los Angeles
Genetics and Genomics
Divya Vats, MD, Los Angeles
Gynecologic Oncology
Scott E. Lentz, MD, FACS, Los Angeles
Devansu Tewari, MD, MBA, Orange County
Hematology Oncology
Ashraf, R., Aziz, MD, Orange County
Gary L. Buchshacher Jr., MD, PhD, Los Angeles
Sujatha Murali, MD, San Marcos
Eric McGary, MD, PhD, MPH, Los Angeles
Helen Moon, MD, Riverside
Hepatology
Amandeep Sahota, MD, Los Angeles
Infectious Diseases
William J. Towner, MD, FACP, FIDSA, Los Angeles
Jonathan Truong, MD, Antelope Valley
Nephrology
Stephanie Cheung, MD, Orange County
John J. Sim, MD, Los Angeles
Hui Xue, MD, MSc, San Diego
Neurology
Annette Langer-Gould, MD, Los Angeles
Abel Wu, MD, Los Angeles
Neurology-Oncology
Richard Green, MD, Los Angeles
Neurology-Vascular (Stroke)
Zahra A. Ajani, MD, Los Angeles
Pamela Cheng, DO, Los Angeles
William Neil, MD, San Diego
Navdeep Sangha, MD, Los Angeles
Shayandokht Taleb, MD, Los Angeles
Neurosurgery
Harsimran S. Brara, MD, FAANS, Los Angeles
Vaninder Chhabra, MD, San Bernardino County
Ophthalmology
Michelle Britt, MD, Baldwin Park
Vivienne S. Hau, MD, PhD, Riverside
Damien Rodger, MD, PhD, Los Angeles
Neil M. Vyas, MD, Panorama City
Kapil M. Sampat, DO, Riverside
Neepa Shah, MD, Riverside
Orthopedics
Jeffrey I. Kessler, MD, Los Angeles
Pediatric Oncology
Robert M. Cooper, MD, Los Angeles
Pediatric Pulmonology
Muhammad Saeed, MD, Los Angeles
Pulmonary
Kenneth Wei, MD, Los Angeles
Radiology – Interventional
Michael Girard, MD, San Diego
Radiation Oncology
Aakash Batra, MD, Bellflower
Radiology – Neuroradiology
Lei Feng, MD, PhD, Los Angeles
Conrad Liang, MD, PhD, San Bernardino County
Rheumatology
Steve S. Lee, DO, San Bernardino County
Andrew Nguyen, MD, Orange County
Sleep Medicine
Prasanth Manthena, MD, Los Angeles
Surgical Oncology
Vikram Attaluri, MD, FACS, FASCRS, Los Angeles
Elisabeth McLemore, MD, FACS, Los Angeles
Urogynecology
Kimberly Ferrante, MD, MAS, San Diego
Shawn A. Menefee, MD, San Diego
John N. Nguyen, MD, Downey
Emily L. Whitcomb, MD, MAS, Orange County
Vascular Surgery
Catherine Chang, MD, San Diego
Linda Chun, MD, Los Angeles
Edward Plecha, MD, San Diego
Division of Clinician Research
Physician director and chair of Regional Research Committee
Bechien U. Wu, MD, MPH, Gastroenterology, Los Angeles
2025 Regional Research Committee
Antelope Valley
Jonathan Truong, MD, area research chair
David Bronstein, MD, vice area research chair
Baldwin Park
Gaurav Khanna, MD, area research chair
Bobeck S. Modjtahedi, MD, vice area research chair
Downey
Eugene A. Chu, MD, area research chair
Rajeev Attam, MD, vice area research chair
Los Angeles
Mingsum Lee, MD, area research chair
Javed Sheikh, MD, vice area research chair
Orange County
Emily L. Whitcomb, MD, MAS, area research chair
Ali Ghobadi, MD, vice area research chair
Panorama City
Ahmed Dehal, MD, area research chair
Regional Laboratory
Darryl Palmer-Toy, MD, PhD, area research chair
Riverside
Rachid A. Elkoustaf, MD, area research chair
Vivienne S. Hau, MD, vice area research chair
San Bernardino County
Conrad Liang, MD, PhD, area research chair
Steve S. Lee, DO, vice area research chair
San Diego
Shawn A. Menefee, MD, area research chair
South Bay
David S. Cohen, MD, area research chair
West Los Angeles/Kern County
Michael J. Fassett, MD, area research chair
Daniel T. Lang, MD, vice area research chair
Woodland Hills/Ventura County
Armen Aboulian, MD, area research chair
Monique George, MD, vice area research chair
Department of Research & Evaluation
Deborah Rohm Young, PhD, MBA, area research chair
Clinician Investigator Program
2025 appointees
Christopher Filson, MD, MS (2025-2028)
Cheng-Wei Huang, MD (2023–2025)
Dennis Hwang, MD (2019–2021, 2023–2025)
Richard Treger, MD (2024-2026)
Yvonne Tsai, MD (2025-2028)
Previous appointees
Raymond Chen, MD, DPhil (2016–2018)
Fu-Sheng Chou, MD, PhD (2022–2024)
Ahmed Dehal, MD, MPH, FACS, FSSO, FRCS (2022–2024)
Kimberly Ferrante, MD, MAS (2019–2021)
Mingsum Lee, MD, MPH (2021–2023)
Bobeck S. Modjtahedi, MD (2018–2020, 2020–2022)
Casey K. Ng, MD (2017–2019)
Chileshe Nkonde-Price, MD, MS, FACC (2021-2023)
Chunyuan Qiu, MD, MS (2018-2020, 2020-2022)
Joan J. Ryoo, MD, MSHS (2018–2020)
Navdeep Sangha, MD (2017–2019)
John J. Sim, MD (2016–2018)
Devansu Tewari, MD, MBA (2016–2018)
Emily L. Whitcomb, MD, MAS (2017–2019)
Bechien U. Wu, MD, MPH (2017–2019)
Hui Xue, MD, MMSc (2016–2018, 2018–2020)
Affiliated researchers
Kaiser Permanente affiliated investigators, including active and retired SCPMG partners:
Bradley Ackerson, MD
David Braun, MD
Jeffrey Brettler, MD
Sirichai Chayasirisobhon, MD, FAAN
Suresh Gurbani, MD
David Harmon, MD
Michael Kanter, MD
Annette Langer-Gould, MD, PhD
Ron Loo, MD
Neal Lonky, MD
Eric Macy, MD
Lisa Nyberg, MD, MPH, MS
Jonathan Polikoff, MD
David Sacks, MD
Michael Schatz, MD, MS
Joanne E. Schottinger, MD
Steven Steinberg, MD
Warren Shapiro, MD
Lester Thompson, MD
Robert S. Zeiger, MD, PhD
Division of Epidemiologic Research
Scientific director
Kristi Reynolds, PhD, MPH
2025 research scientists
Annette L. Adams, PhD, MPH
Jaejin An, PhD
Chun Chao, PhD, MS
Wansu Chen, PhD, MS
Darios Getahun, MD, PhD, MPH
Reina Haque, PhD, MPH
Rulin Hechter, MD, PhD, MS
Matthew T. Mefford, PhD, MPH
Annette Regan, PhD, MPH
Sara Y. Tartof, PhD, MPH
Hung Fu Tseng, PhD, MPH
2025 postdoctoral research fellows
Talar Habeshian, PhD, MPH
Maheen Humayun, PhD, MPH
Nehaa Khadka, PhD, MPH
Amrita Mukherjee, PhD, MPH
Emily Rayens, PhD, MPH
2025 Epidemic Intelligence Service officers
Casey Luc, PhD, MPH*
Rudy A. Patrick, PhD, MPH*
*Dr. Patrick moved into a role as an epidemiologist and Dr. Luc joined R&E in August 2025.
Investigators from other institutions
Katia Bruxvoort, PhD
Division of Health Services Research & Implementation Science
Interim scientific director
Huong Q. Nguyen, PhD, RN
2025 research scientists
Heidi Brown, MD, MAS (Dr. Brown is also a practicing urogynecologist with SCPMG.)
Karen J. Coleman, PhD, MS
Erin E. Hahn, PhD, MPH
Aniket A. Kawatkar, PhD, MS
Brian S. Mittman, PhD
2025 postdoctoral research fellow
Taynara Formagini, PhD, MSc
Previous annual reports
2024
2023
2022
Feature stories:
- Serving others by joining a cancer clinical trial
- The rise of in-home cardiac rehabilitation
- Cancer research focuses on patients’ total health
- The COVID-19 aftermath: Researchers and physicians seek answers
- Uncovering links between air pollution and COVID-19
- Increasing vaccine equity in Southern California
- Responding to a community outbreak through expanded access
- Research committed to firearm injury prevention
- Understanding racial disparities and outcomes in bariatric surgery
2021
Feature stories:
- Patients are pivotal in COVID-19 vaccine research
- R&E answers key vaccine safety and effectiveness questions
- Simple text-based platform proves powerful for monitoring symptoms after vaccination
- Exceptional collaboration tracks emerging variants in real time
- Beyond the virus: Health impacts of the pandemic
- Physician trailblazers
2020
Feature stories:
- Determining who is most at risk from COVID-19
- Clinical trials bring hope during global pandemic
- Searching for evidence to guide COVID-19 care
- Scientists research masking adherence with communities across the country
- Clinical trials are driving a revolution in stroke care
- CDC disease detectives at KPSC build bridges to national COVID-19 response
2019
2018
2017
Feature stories:
- Targeting outreach to reduce lead levels in children
- Using real-world evidence to inform decision-makers about vaccine effectiveness
- Creating better ways to determine hypertension in children and exploring disparities in hypertension
- Producing real-world evidence from our cancer clinical trials
- Finding solutions to real-world clinical problems is what fuels our biostatisticians
- Developing decision-support tools that allow physicians in easily determine risk


