Research Center Team

Dr. Kathy Bowles, vanAmeringen Chair in Nursing Excellence & Professor of Nursing at University of Pennsylvania School of Nursing, joined the Center for Home Care Policy & Research as Director and Vice President in the summer of 2014. Dr. Bowles leads the Center to advance knowledge that will promote the delivery of high-quality, cost-effective care in the home and community, and support informed decision making by policymakers, managers, practitioners, and consumers of home- and community-based services.

Dr. Bowles has a 20-year career with a record of continuous funding from the NIH and other sources for her program of research using information technology to improve care for older adults, and has been nationally and internationally recognized for her research achievements in decision science and telehealth. She has served on the National Quality Forum Care Coordination Steering Committee and consulted for The Centers for Medicare & Medicaid Services (CMS) on its initiative to identify the key data elements essential to safe patient transitions. She has served on CMS’ Technical Expert Panel on the development of the CARE tool and was a member of the Heath Information Technology Standards Panel (HITSP) Care Coordination Committee to identify standards for the electronic health record. She co-founded a software company, RightCare Solutions in 2011 that was recently acquired by NaviHealth and provides an end-to-end solution for discharge planning and post-acute care management. Most recently she was appointed to the National Advisory Council of the National Institute of Nursing Research, National Institute of Health.

Dr. Bowles holds a BSN from Edinboro University of Pennsylvania, an MSN from Villanova University, and a PhD from the University of Pennsylvania. Dr. Bowles is a Senior Fellow in the Leonard Davis Institute, and Director of the Health Informatics Minor at Penn Nursing. She is an elected fellow in the American Academy of Nursing (AAN) and the American College of Medical Informatics and a member of the American Nurses Association (ANA), the Gerontological Society of America, the American Medical Informatics Association, and Sigma Theta Tau International Honor Society.

Kathryn Bowles CV

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Margaret McDonald, MSW, Associate Vice President, joined the Center for Home Care Policy & Research in 1998. At the Center, she is responsible for developing and conducting research studies as well as overseeing grants and center administration. In the administrator role, she oversees a team that prepares and submits National Institutes of Health grant proposals and management of the Center’s internal finances and legal affairs. She holds the role of Data Security and Compliance Officer for Research and Administrator of the VNS Health Institutional Review Board. In her scientific role, Margaret has extensive experience in helping multi-institution collaborative investigative teams develop, apply for, implement, and disseminate the results of research studies ranging from small pilot studies to large, federally funded randomized controlled trials. Ms. McDonald has been the co-investigator or Project Director on a number of large Agency for Healthcare Research and Quality (AHRQ), National Institutes of Health (NIH), and foundation-sponsored projects.

The focus of her work has been on examining the characteristics and needs of the home health population, developing risk prediction models, and evaluation of the quality, comparative effectiveness and outcomes of home health interventions. Margaret has co-authored over 70 peer reviewed articles, which highlights successful cross-disciplinary research collaboration contributing to the improvement of care for older adults with chronic, complex, and advanced illness.

Margaret is a graduate of New York University’s Stern School of Business and received a Master of Social Work degree with a concentration in research from Fordham University. Before joining VNS Health, Ms. McDonald worked with Memorial Sloan Kettering Cancer Center’s Psychiatry and Pain Service and the Oncology Symptom Control Research Group at Community Cancer Care of Indiana. The research that she was involved in focused on symptom management in cancer and AIDS patients.

Margaret McDonald CV

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Barbara Riegel, PhD, RN, is a Senior Research Scientist at the Center for Home Care Policy & Research at VNS Health, a Professor Emerita in the School of Nursing at the University of Pennsylvania, a Professorial Fellow at Australian Catholic University, and Co-Director of International Center for Self-Care Research. Her program of research addresses self-care broadly defined to embrace treatment adherence, condition monitoring, and symptom management. Dr. Riegel began studying these issues early in her career while a Clinical Researcher in an acute care setting when hospitals were just beginning to recognize that heart failure was a primary reason for hospital readmissions. She has developed theory and self-report measures of self-care that are used worldwide (www.self-care-measures.com).  She has received numerous awards for her research including the Distinguished Scientist Award from American Heart Association and Sigma Theta Tau International Nurse Researcher Hall of Fame. She is listed as one of the Best Female Scientists in the US by www.Research.com. Dr. Riegel has published widely, with more than 375 peer reviewed articles. She has been consistently funded for her research since 1990, with grants from the National Institutes of Health and private foundations such as the American Heart Association.

David Russell, PhD, is a Research Scientist in the Center for Home Care Policy & Research at the VNS Health. Dr. Russell transitioned to a part-time role at the Center in June 2017 upon accepting a position as Assistant Professor of Sociology at Appalachian State University.

Dr. Russell is a medical sociologist with interests in social disparities in long-term and end-of-life health care outcomes, workforce initiatives, and health care technology. He has substantial experience evaluating new programs and initiatives at the agency, as well as in using secondary electronic clinical data sources (e.g. medical records, clinical assessments, service utilization information) to identify patterns in health care outcomes among VNS Health patients and VNS Health CHOICE Health Plan members. His recent work includes an examination of continuity in visiting nurse personnel and its implications for the patient experience, an evaluation of a workforce initiative to prepare home health aides as health coaches, and an investigation into the frequency and correlates of distinct live discharge outcomes among hospice patients.

Dr. Russell has published widely in the fields of health services, gerontology, and medical sociology. He was twice awarded the Impact Article of the Year in 2011 and 2012 by the National Association for Healthcare Quality. Prior to joining the Center, Dr. Russell was an NIMH Postdoctoral Trainee at the Institute for Health, Health Care Policy, and Aging Research (Rutgers University). His work at the Institute focused on the ways in which community and household integration shape risk for physical and mental health problems among older adults. Dr. Russell received his PhD in Sociology from Florida State University in 2007.

David Russell CV

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Julia Burgdorf, PhD, is a Research Scientist at the Center for Home Care Policy & Research at VNS Health.

Dr. Burgdorf is a health services researcher who specializes in leveraging population-level linked claims, assessment, and survey data to examine the complex landscape of social and structural factors impacting home health care accessibility and quality for older adults. She is especially interested in better understanding the role of family caregivers during home health care and developing system-based strategies to improve communication and collaboration between clinicians and family caregivers, with a focus on families and patients experiencing dementia. Dr. Burgdorf is experienced in both quantitative and qualitative research methods, employing whatever approach is best-suited to the question at hand.

Prior to joining the Center, Dr. Burgdorf was a National Institute on Aging Ruth L. Kirschstein postdoctoral fellow at the Johns Hopkins Bloomberg School of Public Health. She received her PhD in Health Services Research from the Johns Hopkins Bloomberg School of Public Health in 2020 and continues to work closely with researchers in the Department of Health Policy & Management at Johns Hopkins School of Public Health as a Faculty Associate. Dr. Burgdorf also has a BS in Policy Analysis & Management from Cornell University.

Julia Burgdorf CV

Dr. Maxim (Max) Topaz PhD, RN, MA joined VNS Health’s Center for Home Care Policy & Research in 2018 as Associate Professor of Nursing under a joint-appointment with the Columbia University Medical Center and the Columbia University Data Science Institute, where he is the Elizabeth Standish Gill Associate Professor of Nursing. Dr. Topaz’s clinical experience is in internal and urgent medicine. His research primarily involves leveraging technological and computer science breakthroughs to develop and utilize informatics methodologies, like text and data mining, to evaluate and inform health and home care provision practices and policy, as well as the fields of data science and health informatics methods science generally. Dr. Topaz has authored more than fifty articles on topics related to health informatics and received numerous prestigious awards for his work. His current work focuses on developing natural language processing solutions for big data in health care.

Dr. Topaz’s roles at the Center include collaborating with Center Leadership and staff to determine critical research and practice issues, providing leadership, expertise and efforts in the conceptualization, design, conduct, dissemination, and translation of the Center’s research, and generally, supporting and advancing the research mission and goals of the Center. Dr. Topaz is also responsible for obtaining external funding for and leading nationally-significant, high- quality, practice and/or policy-relevant research in areas at the intersection of nursing, home health care, informatics, technology, and the larger health care system.

Prior to joining the Center, Dr. Topaz was involved with health policy (national and international levels), leadership (e.g. Chair of the Emerging Professionals Working Group of the International Medical Informatics Association) and health entrepreneurship. He served as a Senior Lecturer at the School of Nursing, University of Haifa (Israel) where he led the Health Information Technology Lab.

Dr. Topaz earned his PhD degree in Nursing as a Fulbright Fellow at the University of Pennsylvania and his Masters (Cum Laude) and Bachelors degrees from the University of Haifa, Israel. He completed a postdoctoral fellowship in Medicine at the Harvard Medical School and Brigham Women’s Hospital.

Maxim Topaz CV

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Miriam Ryvicker, PhD, is a Senior Research Scientist at the Center for Home Care Policy & Research of the VNS Health. Her primary research focus is on racial and socioeconomic disparities in access to and quality of health care for older adults with chronic illness. She has led several studies funded by the National Institute on Aging / National Institutes of Health using advanced data science methodologies to examine health service utilization and outcomes among Medicare beneficiaries with chronic conditions such as heart failure, diabetes, and Alzheimer’s Disease and related dementias. This body of work includes research on the role of neighborhood characteristics in access to health care for older adults living in New York City. Dr. Ryvicker has conducted analysis for randomized trials of organizational and behavioral interventions to improve the ability of home care patients to manage their health and health care. She has also led large-scale program evaluations of several home health care workforce development initiatives.

Dr. Ryvicker received her PhD in sociology from New York University in 2007. Her dissertation research was a qualitative study of nursing home organizational culture and quality of life, funded by a Health Services Dissertation Grant from the Agency for Healthcare Research and Quality (AHRQ), US Department of Health and Human Services. Dr. Ryvicker also has a BA in urban studies from Brown University.

Miriam Ryvicker CV

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Timothy Peng, PhD, Chief Data Analytics Officer for VNS Health at large, joined the Center for Home Care Policy & Research in July of 1998 as a Research Scientist. At the Center, he was responsible for conducting research on the quality and outcomes of home health care, and the effects of public policy on long-term care. His research also examined potential disparities in access to care and health outcomes of chronically disabled elders from different ethnic backgrounds and socioeconomic groups.

In 2018, Tim was promoted into the newly-created Chief Data Analytics Officer role for VNS Health, responsible for providing enterprise-wide staff at all levels with meaningful, timely, directive data, analysis, interpretation, and guidance backed by empirical evidence and research. Business needs addressed include payment and reimbursement policy planning and analysis; quality measurement and monitoring; program evaluation; customer satisfaction; clinical, operational and financial outcomes; operations analysis; performance monitoring and improvement. Also responsible for conducting scientifically rigorous research on: understanding and improving patient outcomes; access to long-term care; quality measurement; payment systems and provider response to policy incentives; value-based purchasing; and chronic disease management in clinically complex patient populations. Duties include developing testable hypotheses from business questions; providing empirical guidance to executive leadership and operational managers; conducting analyses to drive business and operational strategy and efficiency; integrating logic and analysis into workflows and processes; and general supervision and administration of the VNS Health Outcomes, Business Intelligence, Analytics, and Health Care Economics teams, who supply VNS Health leadership and clinical teams with health care provision analytics, while contributing data analytic and infrastructure support and expertise, as well as staff, to Research Center projects.

Alexis Stern, Research Analyst II, joined the Center for Home Care Policy & Research in 1999. She currently works with Miriam Ryvicker on efforts to expand the reach of the Center’s scientific research findings and optimize their use in informing decision-making and implementing evidence-based programs and practices across VNS Health lines of business. Alexis also supports the VNS Health Veterans Program by conducting the Program’s data collection, data analysis, and program evaluation activities. Finally, as a Research Interviewer for the longitudinal Gender Affirmation Program Study, Alexis interviews participants about their healthcare and quality of life after gender affirming surgery.

During her years at VNS Health, Alexis’ responsibilities have included project management, communications, grant reporting, grant proposal submissions, research, data collection, program evaluation, and research analysis. Over the years, Alexis has worked on a variety of Research Center projects and programs, including the AdvantAge Initiative (a program that helped communities measure their elder-friendliness and enhance older residents’ ability to age in place); CHAMP (Collaboration for Homecare Advances in Management and Practice); the Administration on Aging-funded CIAIP (Community Innovations for Aging in Place) project; the Health Indicators in NORC Programs Initiative; the Home Care Research Initiative (HCRI); and the Multi-Regional Model to Increase the Proportion of Baccalaureate Nurses (RIBN) in New York City and North Carolina.

Alexis has also worked for other nonprofit organizations and institutions, including Columbia University’s Mailman School of Public Health, New York University, the International Longevity Center, Food & Hunger Hotline, and as a science teacher in New York City elementary schools.

Elliot Smith joined the Center as a Research Interviewer in 2024. As a research interviewer, he recruits participants and conducts in-depth interviews assessing participants’ relationship with healthcare, their psychosocial development, and overall quality of life. Elliot has a BA in Forensic Psychology from John Jay College of Criminal Justice (2023) where he worked as a research assistant in a cognition lab. During his time at John Jay, he focused on therapeutic treatments for PTSD and developed a framework for treating cases of sociogenic illness in the age of social media. He is currently pursuing a master’s degree in Mental Health Counseling.

Felix Vasquez, BS, Research Assistant, joined the Center for Home Care Policy & Research as a Research Interviewer in early 2019 as an interviewer on the CAPABLE study, and began working full-time at the Center in 2021 as a Research Assistant.

At the Center, Felix is responsible for recruiting and interviewing study participants, data entry, and reviewing patient interviews. He graduated from SUNY Stony Brook in May 2018 with both a Bachelor of Science in Chemistry and Biochemistry. Felix had worked alongside a researcher on the structural characterization of proteins during his time at Stony Brook. Before joining VNS Health, he had worked as a customer care representative and returns agent. More recently, he helped to do his part in preventing the spread of COVID-19 when he joined our efforts in vaccinating VNS Health as a member of our clinic.

Greg Horton, BFA, Business Manager, Research Studies, rejoined the Center for Home Care Policy & Research in 2021 following previous administrative work for the Center from 1996 to 2003. At the Center, he provides administrative and research support to the research staff, manages grant submissions and grant and financial administration, and is responsible for ensuring the Center’s internal and external research and administrative compliance. He also serves as coordinator and liaison between the Center and VNS Health’s Legal, IT, Procurement, and HR departments, and works with VNS Health Marketing and Enterprise Communications to manage the Center’s online presence.

Mr. Horton graduated with a BFA from Syracuse University in 1986 with a degree in Musical Theater. After his previous work for the Center, he moved on to working with the VNS Health Chief Executive Office as Administrative Assistant and then to the VNS Health Performance and Innovation Department as Executive Assistant to the SVP and Department Coordinator. From 2016 to 2021, he worked as the Administrator for the fertility clinic start-up Extend Fertility. As an actor, he has performed in regional theatre, on tour, on a Mississippi steamboat, as well as multiple shows Off and Off-Off Broadway, and is the winner of two New York Innovative Theatre Awards for Outstanding Actor in a Lead Role.

Grace Flaherty joined the Center for Home Care Policy & Research in October of 2024. She is a recent graduate from Connecticut College with a BA in psychology, as well as in gender, sexuality, and intersectionality studies. Grace has been passionate about research for much of her adult life, and completed her undergraduate research honors thesis in the spring of 2023. The project, entitled Queering the Pandemic: Assessing College Students’ Queer Identity Development Experiences During COVID-19, was an in-depth thematic analysis of a series of interviews that she conducted during her junior and senior year. She recently moved to New York City from her hometown of Portland, Maine after obtaining her degree, and she is beyond excited to continue to nurture her passions at VNS Health!

Ian Spens, MA, Research Assistant, joined the Center for Home Care Policy & Research in late 2023. Ian holds a Master of Arts in Psychology from New York University (2023) and dual Bachelor of Science degrees in Mathematics and Psychology from Clarkson University (2019). Prior to working at VNS, Ian spent time working in a variety of clinical settings ranging from urgent care medicine to psychosocial rehabilitation. These experiences have given Ian invaluable insights into the healthcare system and patients’ experiences, as well as driven their passion to make healthcare more accessible to everyone. As a Research Assistant, Ian is responsible for recruiting patients, data collection, administering cognitive tests, and contributing to publications.

Ilse Luna-Romo joined VNS Health’s Research Center as a Research Interviewer in June 2024. As an Interviewer, Ilse recruits and conducts interviews with English and Spanish speaking participants with the Gender Affirmation Program Study. Ilse is currently pursuing a bachelor’s degree in medical humanities through the Institute of Comparative Literature with a minor in science and society at Columbia University, with an expected graduation date of May 2026. Within her academic career, Ilse has focused on the health of queer Spanish-speaking communities within the United States. They are also involved in on-campus publications and organizations such as the Columbia University Medical Review and Chicanx Caucus.

Lori King, MPH is a Research Analyst who joined the Center for Home Care Policy & Research in September of 2000 where she has primarily worked on quality improvement and access to care projects. Ms. King previously worked on two Agency for Healthcare Research and Quality (AHRQ)–sponsored projects focused on patient safety, Working Conditions and Adverse Events in Home Health Care (WEPS) and Developmental Center for Evaluation and Research in Patient Safety (DCERPS), a collaborative effort with New York University’s Division of Nursing. Prior to this work she worked on a large-scale project sponsored by AHRQ, Translating Research into Practice (TRIP): Evidence-Based ‘Reminders’ in Home Health Care”, which focused on evaluating strategies to promote evidence-based care. Her latest work was sponsored by National Heart Lung and Blood Institute (NHLBI), Interventions to Improve Blood Pressure Control in African Americans, which also focuses on evaluating strategies to promote evidence-based care. Ms. King is responsible for Institutional Review Board (IRB) activities for VNS Health.
Ms. King earned her Masters in Public Health at Columbia University Mailman School of Public Health. Before joining VNS Health, she worked at The National Board of Medical Examiners in Philadelphia, where she worked on the Standardized Patient Project.

Nicole Onorato, MPH, Research Project Manager, joined the Center for Home Care Policy & Research as an intern in 2014 and began working full time for the center in 2016. Nicole graduated in May of 2024 with an MPH from George Washington University Milken Institute of Public Health. For her thesis project, she conceptualized a program to address loneliness and social isolation among older adults living alone in NYC by pairing older adults with cats in foster care and providing services to support their ability to care for the cat. Before joining VNS Health, Nicole worked as a Nurse’s Assistant/ Patient Care Technician from 2008–2016 working on a neurorehabilitation unit of a hospital and in a nursing home.

At the Center, Nicole is responsible for managing teams to recruit subjects into various research studies and complete data collection activities, helping to provide training and support to research assistants and interviewers, and for providing administrative and research support to several senior researchers across multiple projects as well as to the Center in general. She has worked on a wide-range of studies including home health aides and health coaches, post-stroke patients, cancer patients, and studies that aim to provide clinical decision support to home health care clinicians. Currently Nicole is working on a study that examines patient and caregiver knowledge, attitudes, and practices around infection control in the home environment.

Nüma Molière joined the Center for Home Care Policy and Research in October of 2024. They’re a graduate of Loyola University Chicago with a BA in Psychology, as well as a minor in Sociology and Spanish. Nüma moved from Chicago to NYC back in 2018 and began their professional career in research starting at Columbia University, both in the Social Work department looking at how AI can affect racial bias and at the Mailman School of Public Health studying risk and protective factors of women in Kazakhstan towards ART adherence/treatment compliance. Since then, they have entered the world of clinical trials/research and have assisted with Phase I, II, and III interventional trials of MS-related diseases and psychiatric disorders like Schizophrenia and PTSD. They are currently a Clinical Researcher at Weill Cornell Medical School where they research geriatric patient prognostics within the Emergency Department and leveraging AI to assist with patient risk assessment and intervention.

Piotr Kapela is a Statistical Programmer and Analyst who joined the Center for Home Care Policy & Research in January of 2022. Prior joining the Research Center, Piotr worked on various technical positions within Academia and Cultural Institutions helping to deliver large public facing software projects. During his work he developed interest in distributive computing, cloud solutions applied to data intensive applications, and statistical learning methods. At the Center, Piotr is helping researchers on federally funded research studies leveraging data obtained from various VNS Health Health computer systems.

Piotr graduated from CUNY Hunter College with a degree in Computer Science, and hold a Master’s degree in Statistics from CUNY Baruch College.

Sasha Vergez, Research Analyst I, joined the Center for Home Care Policy & Research in early 2019 as an intern on a stroke study and began working full-time at the Center in 2021. In May 2024, Sasha graduated with a MPH concentrated in epidemiology and biostatistics from CUNY School of Public Health & Health Policy. Sasha’s capstone focused on the association between delayed start-of-care visits and negative outcomes such as hospitalizations and emergency department visits. More specifically, Sasha investigated how this relationship was affected among different levels of disadvantaged neighborhoods. Before joining the center, Sasha has worked alongside several CUNY professors on studies focusing on the wellbeing of older adults and of all individuals during the COVID-19 pandemic.

At the Center, Sasha is responsible for recruiting and interviewing study participants, training field staff, and providing administrative research support for ongoing projects. She has worked on a wide range of studies focusing on home health aides and heart failure patients, infection prevention control and safe transitions coming home from hospitals. Sasha is currently working on studies leveraging A.I and speech analysis to identify patients at risk of negative outcomes.

Sonia J. Cheruvillil, DPH, Research Project Manager, joined the Center for Home Care Policy & Research in August of 2021. Sonia is currently managing a multiyear, longitudinal study with Dr. Miriam Ryvicker and Dr. Walter Bockting at Columbia School of Nursing called Gender Affirming Program Study. The study looks at the kind of support that transgender and nonbinary people need from the health care system after gender-affirming surgeries. The study examines the patient experiences of people who have gone through VNS Health’s Gender Affirmation Program.

Sonia has a doctorate in public health (DPH) from the City University of New York (CUNY) School of Public Health and Health Policy in the Department of Community Health and Social Sciences. Her dissertation work looked at mining, climate change and selected health outcomes in India. Prior to this work, she has been an educator and a researcher in areas related to gender, sexuality, human rights, and environmental science.

Sridevi Sridharan, MS, Manager, Analytics Engineer, joined VNS Health’s Center for Home Care Policy & Research as a Consultant in August 2008. Soon after, in December 2008, she joined the center as a full-time staff member. She has a BS in Computer Science and MS in Biomedical Engineering. Prior to joining the center, Sridevi worked as a Statistical Programmer for Health Care and Pharmaceutical companies.

At the Center, Sridevi works closely with the Research Center Project Managers and assists in the design and implementation of patient enrollment for research studies, produces statistical summaries and quantitative analyses. She is currently working on the following projects: Cognitive-Behavioral Pain Self-Management, Washington Heights / Inwood Informatics Infrastructure for Community-Centered Comparative Effectiveness Research, Home-Based Blood Pressure Interventions for African Americans, Improving Medication Management Practices and Center for Stroke Disparities Solutions.

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Yolanda Barrón-Vayá, MS, Senior Biostatistician, joined the Center for Home Care Policy & Research in September 2011. Ms. Barrón is currently working in the analysis of the “Improving Medication Management Practices and Care Transitions through Technology (IMPACT)” project, a randomized trial to examine the effectiveness of a comprehensive information technology (IT) strategy to improve medication management for home health patients at risk of potentially serious medication problems due to the complexity of their medication regimen.

Prior to joining the center, Ms. Barrón worked as a biostatistician at the Pain Research Group at the University of Wisconsin-Madison. She later became a member of the Biostatistical Consulting Core and the Dana Center for Preventive Ophthalmology at the Wilmer Eye Institute in Johns Hopkins, before joining the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health as a statistical programmer, where she collaborated with investigators from the Women’s Interagency HIV Study (WIHS), a multicenter cohort study of the natural history of HIV-1 infection in women in the United States.

In 2005, Ms. Barrón joined the Division of Biostatistics and Epidemiology at Weill Cornell Medical College, where she collaborated with Weill Cornell and VNS Health investigators in the design and analysis of a longitudinal multilevel study on the effect of the Patient Activation Measure on chronic care of patients with hypertension. She later worked with members of the Division of Quality and Medical Informatics at Weill Cornell in the design and analysis of studies to evaluate the effects of health information technology (HIT) and health information exchange (HIE) on quality of care and medication safety through the HEAL NY initiatives. Ms. Barrón was also the co-director of the course “Introduction to Biostatistics in Clinical Research” for the Masters Program in Clinical Investigation, part of the Clinical and Translational Science Center (CTSC) at Weill Cornell Medical College.

Ms. Barrón received a MS in Statistics from the University of Wisconsin-Madison, and a BS in Applied Mathematics from the Instituto Tecnológico Autónomo de México (ITAM).

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