Post-Doctoral Fellows

 Post-Doctoral Fellows

Sarah Axeen, Ph.D., is a Schaeffer-Amgen Post-Doctoral Fellow with the Schaeffer Center for Health Policy and Economics and the Fielding School of Public Health at the University of California at Los Angeles. She graduated from the USC Price School of Public Policy in 2016 with a doctorate in Public Policy and Management.

Dr. Axeen’s current research focuses on understanding drivers of and evaluating solutions to the growing problem of opioid use and abuse in the United States. In addition to her research on opioids, she has explored geographic variation in health care and co-authored a paper in Health Services Research with colleagues at the Schaeffer Center on the relationship between changes in commercial prices and spending and utilization in Medicare. Prior to graduate school, she served as an Assistant Analyst in the health division of the Congressional Budget Office and received her bachelor’s degree in Public Policy Analysis from Pomona College.



Douglas Barthold, Ph.D. is a Schaeffer-Amgen Post-Doctoral Fellow at the Schaeffer Center for Health Policy and Economics at the University of Southern California. He received his Ph.D. in Economics from McGill University in 2015, with health economics as his primary field of specialization. He completed his undergraduate studies in Economics at the University of Massachusetts, Amherst in 2007. 

Doug’s research focuses on health insurance design, and on the role of health policy in influencing health care utilization, health outcomes, and inequality. His dissertation analyzes effects of prescription drug cost sharing, including cross-price effects on complementary service utilization, and offset effects on preventable hospitalizations and emergency department visits. Other current research examines effects of health insurance eligibility expansions on the intergenerational transmission of socioeconomic status. Past work included multi-level modeling of the relationship between diabetes diagnoses and labor force participation, and longitudinal health system efficiency analyses in the OECD.

To read more about Douglas Barthold, please visit his website:

Welmoed van Deen, Ph.D.  started her undergraduate studies in biomedical sciences at Leiden University, The Netherlands in 2004. After receiving a B.S. in biomedical sciences in 2007 she enrolled in medical school at Leiden University, The Netherlands. During medical school she spent three months in Zambia and three month in Tanzania, and received her M.D. in December, 2011 after doing her final clinical rotation in the Department of Gastroenterology and Hepatology at the Leiden University Medical Center. In January, 2012, Welmoed started her Ph.D. studies in 2012 at Leiden University under the supervision of Professor Daniel W. Hommes. After receiving three months of research training at the Department of Gastroenterology and Hepatology at the Leiden University Medical Center she moved to Boston, Massachusetts in the United States, where she worked in the lab of Dr. Dimitrios Iliopoulos at the Dana Farber Cancer Institute at Harvard University. In July, 2012 she started her work in value-based health care at the Center for Inflammatory Bowel Diseases at the University of California, Los Angeles in the United States. Welmoed is a member of the International Consortium for Health Outcomes Measurement (ICHOM) Inflammatory Bowel Diseases Working Group, in which she works with a team of leading experts to develop an internationally recognized set of outcome metrics for inflammatory bowel diseases. Welmoed has now finished her thesis titled "Value-Based Health Care in Inflammatory Bowel Diseases" and received her Ph.D. in Medicine in March, 2016 at Leiden University, The Netherlands.

Currently she is an assistant research professor at the USC Gehr Family Center for Implementation Science and am conducting a part-time Schaeffer-Amgen Fellowship at the Schaeffer Center. She is planning to expand her work in value-base health care in chronic disease management. 

Ilene Hollin, Ph.D. is a postdoctoral fellow at the Leonard D. Schaeffer Center for Health Policy and Economics and the National Pharmaceutical Council.  She  recently completed her doctoral studies at Johns Hopkins Bloomberg School of Public Health in the Department of Health Policy and Management. Her degree is in health economics and policy, specializing in economic evaluation. She also earned a Certificate in Public Health Informatics.  She received her MPH in effectiveness and outcomes research from Columbia University and her BA in American studies and international and global studies from Brandeis University. Ilene has worked as a program specialist at the Office of the National Coordinator for Health Information Technology. She was the 2013-2014 Johns Hopkins Center to Eliminate Cardiovascular Disparities Research Fellow and the 2011-2013 recipient of the training grant fellowship from the Division of Health Science Informatics. She is the recipient of the 2015 Alison Snow Jones Memorial Prize, the 2014 Charles D. Flagle Award and the 2013 Lee Lusted Student Prize in Decision Psychology and Shared Decision Making.

Ilene’s research interests include patient preferences, patient-centered benefit-risk assessment, access and affordability of healthcare, the impact of health economics and policy on decision-making, and the value of health IT. She is particularly interested in rare disease and pediatric applications. Ilene's dissertation research focused on patient-centered drug development for Duchenne muscular dystrophy.

Bo Zhou, Ph.D. is a postdoctoral fellow at the Leonard D. Schaeffer Center for Health Policy and Economics at the Unviersity of Southern California. She graduated with a Ph.D. in economics from the University of Southern California in 2014. Before pursuing her Ph.D., she obtained her M. Sc. in physics at McMaster University in Canada.

Her research focuses on health ecnomics and econometrics. Her dissertation studies applications of Markov switching models in economics. She runs simulations of perspective spending in Medicare Part D and analyzes beneficiaires' switching behavior using detailed administrative data, including determinants of switching, costs of switching and the role of inattention in consumer inertia. In addition, her research interest extends to applications of Hidden Markov models in estimating change in health conditions.

To read more about Bo Zhou visit her website at
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