Leadership Team

being the change that drives healthcare improvements

“I’ve learned that people will forget what you said, people will forget what you did,
but people will never forget how you made them feel.” —Maya Angelou

Winifred S. Hayes, RN, PhD, ANP

Wini_Hayes_healthcare_presidentFounder and CEO

Dr. Hayes founded Hayes, Inc. in 1989 in response to a growing need in the healthcare industry for evidence-based assessments of health technologies. Under her leadership, Hayes, Inc. has become an industry leader in providing unbiased, timely, clinically focused, evidence-based research and analysis to health plans, insurers, hospitals, healthcare systems, ACOs and government agencies. In June 1999, in response to the public outcry for independent, external medical review within the healthcare industry, Dr. Hayes formed Hayes Plus, a national Independent Review Organization. She sold the company in October 2005 after it was firmly established in the marketplace.

Dr. Hayes was a founding member and the first President of the National Association of Independent Review Organizations (NAIRO). She currently serves on the Board of Directors for URAC, an independent, nonprofit organization that is a leader in promoting healthcare quality through its accreditation and education programs. She is also a member of Health Technology Assessment International and Vistage, an international organization of CEOs dedicated to increasing the effectiveness of chief executives and those they influence. In addition, Dr. Hayes is an Associate of the Women Business Leaders of the U.S. Health Care Industry Foundation™ (WBL).

In 2000, Dr. Hayes received the Women of Distinction Award in the Greater Philadelphia area and in 2001 was selected as one of “Pennsylvania’s Best 50 Women in Business.” Both award programs acknowledge the personal and professional achievements of Pennsylvania businesswomen and their contributions to our economy.

Her expertise as both a clinician and consultant has made her one of the leading experts in the fields of evidence-based health technology assessments, utilization review, and clinical guideline development, as well as a sought-after speaker. Dr. Hayes publishes and lectures to managed care organizations and healthcare associations throughout the United States as an advocate for evidence-based decision making and its vital contribution to improving patient outcomes and healthcare resource allocation.

Dr. Hayes received her Doctor of Philosophy degree from the Johns Hopkins University School of Hygiene and Public Health (Bloomberg School of Public Health). A graduate of the University of Maryland School of Nursing, with Primary Care Nurse Practitioner and Master of Science degrees, she has served as an Associate Professor and Program Director for the Occupational Health Nursing Graduate Program at the University of Pennsylvania School of Nursing. She also served on the faculties of Emory University and the University of Maryland. She is currently affiliated with the Senior Scholars Program in the Department of Health Policy at the Jefferson Medical College.


Maura Connor

Maura_Connor_Chief_Operating_OfficerChief Operating Officer

Ms. Connor joined Hayes in August 2014 as Vice President/Editor-in-Chief and was soon after named Chief Operating Officer. Ms. Connor oversees Hayes’ daily operations, including digital publishing, product strategy and innovation, marketing, client fulfillment services, and accredited continuing education programs.

Prior to joining Hayes, Ms. Connor served in various positions of increasing responsibility in product development, most recently as Associate Vice President/Director of Digital Products and Strategy at Pearson Education. In this role, Ms. Connor led a business unit focused on delivering integrated enterprise curricular integrated digital learning, testing, and analytic reporting solutions for higher education institutions. She also built and led successful product teams for over a decade as Assistant Vice President/Editor-in-Chief at Pearson.

Before joining Pearson, she worked in various roles in acquisitions, product management, marketing, and educational sales. During her tenure at W.B. Saunders/Harcourt Health Sciences, Ms. Connor managed a publishing program that consisted of academic nursing textbooks, professional certification curricula and references, and digital products. She also served as chief publishing liaison to numerous professional nursing organizations, including AWHONN, ASPEN, AORN, INS, ASPAN, AANA, and NANN, among others.

Ms. Connor earned her BA in English and History with a minor in premedical studies from Duke University. She also completed the Stanford University Medical Informatics Short Program.

Christina G. Dietrich

Christina_Dietrich_chief-financial-officerChief Financial Officer

Ms. Dietrich joined Hayes in 1999. She is responsible for assessing and evaluating the financial performance of the organization with regard to operational goals, budgets and forecasts. Christina oversees the operations in connection with financial and administrative matters including accounts receivable and payable, payroll and HR. She trains and supervises departmental staff; develops and initiates systems, policies and procedures for transacting financial and other administrative matters, and in coordination with an external CPA firm, ensures that the financial system is accurate, efficient, and in accordance with professional accounting practices and governmental regulations.

Ms. Dietrich earned her BS degree in Accounting at the University of Bridgeport, a BA in Geology at Guilford College, and an MS degree in Geology at Lehigh University.

David Zieve, MD, MHA

david_zieve_medical_directorMedical Director

Dr. David Zieve joined Hayes in October 2016 as Medical Director. Dr. Zieve works closely with the Evidence Solutions analysts, as well as provides clinical oversight for a variety of client solutions, including collaborations with Hayes’ key clients. With his extensive experience in developing evidence-based clinical guidelines, his additional background in utilization management and policy development, and his clinical expertise, Dr. Zieve contributes greatly to the strategic vision of the organization.

Prior to joining Hayes, Dr. Zieve served in various medical director positions, most recently as Senior Medical Director of Health Integrated, where his role encompassed utilization management, appeals management, case management oversight, and medical policy. Dr. Zieve also worked as a Physician Editor for Milliman Care Guidelines (now MCG). There he wrote and edited evidence-based clinical care guidelines, including coverage of emerging technology and pharmaceuticals, and worked with analysts to create utilization benchmarks.

Dr. Zieve also worked as Medical Director for A.D.A.M. Health, provider of patient education content; as a Physician Adviser with the Health Information Institute; and as Vice President and Medical Director, Quality and Utilization Management, and Clinic Medical Director at Medalia Healthcare/Providence Health System.

Dr. Zieve earned his Doctor of Medicine from the Medical College of Ohio (now the University of Toledo Medical School), completed his Family Practice Residency at the University of Wisconsin, Madison, and is Board Certified by the American Board of Family Medicine. He also holds a Master of Health Administration from the University of Washington.

Varghese Jacob

Director of Information Technology & Digital Publishing Platforms 

Mr. Jacob joined Hayes in April 2017 as the Director of Information Technology & Digital Publishing Platforms. His extensive amount of time in the scientific, technical, and medical information industries allows him to guide the Hayes technology team and lead the company’s digital transformation. Mr. Jacob is responsible for technology product management and development, including utilizing his strategic insight and his content management knowledge to adapt Hayes’ digital publishing platform and content to address the unmet needs of Hayes’ health plan and health system clients. He is also tasked with staff leadership and development for the IT and digital production teams.

Prior to joining Hayes, Mr. Jacob served as the Principal Solutions Architect at HCL America. His additional professional experience includes acting as the IT Operations Manager, The Agency Inside and as the Software Development Manager, Principal Software Engineer, and Project Manager for the health sciences and Science and technology divisions of Elsevier, Inc.

Mr. Jacob holds a Bachelor of Science Degree in Biochemistry from Temple University. In addition to his vast technical proficiencies in software architecture and digital transformation, Mr. Jacob has extensive experience in software product development, project management, and IT operations.


Petra Nass, PhD

Petra_Nass_health_researchSenior Scientific Officer
Director, Research, Innovation, and Quality Assurance

Dr. Nass is responsible for product innovation and for ensuring the scientific and methodological quality of the Hayes evidence products. Dr. Nass also provides scientific support for the genetic testing and horizon scanning solutions. In previous roles at Hayes, she was product manager of the Hayes Medical Technology Directory and has led custom projects for key clients. She has written and edited over 100 health technology assessments or comparative effectiveness reviews.

Prior to joining Hayes, Dr. Nass was a faculty member of the Johns Hopkins University and a postdoctoral fellow at the Food and Drug Administration. She developed plasmid vectors for gene therapy for herpes simplex virus and wound healing, and supported projects on molecular markers in esophageal cancer. This work resulted in peer-reviewed publications.

Dr. Nass has a broad understanding of research strategies and methods encompassing the natural and social sciences. Continuing education and certification in public policy and management (University of York, York, United Kingdom), cross-cultural training and management (Heidelberg University of Education, Heidelberg, Germany), systemic and integrative therapy (Psynapse School of Psychotherapy, Paris, France), and computational genomics and executive data science (Johns Hopkins University, Baltimore, USA) complement her professional experience.