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The Medical Center of Aurora

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Executive Team

Miller, Dan-72dpi

Dan Miller, FACHE
President & Chief Executive Officer

Dan Miller joined The Medical Center of Aurora in 2015 from Swedish Medical Center. At TMCA, Dan oversees the medical center’s four campuses, which include two freestanding ERs (Centennial Medical Plaza and Saddle Rock ER), and an array of services, including a Level II Trauma Center, and a comprehensive cardiovascular program with two accredited Chest Pain Centers and a new TAVR program. In addition, TMCA is a Joint Commission Accredited Primary Stroke Center, and the HealthONE Behavioral Health Services hospital.

While COO at Swedish, Dan oversaw the opening of a new Burn Critical Care Unit and Outpatient Clinic. He also lead the development of the comprehensive cancer program allowing Swedish to become the third hospital in the country to be pancreatic cancer accredited and the fifth in the country to be lung cancer accredited by The Joint Commission. Additionally, Miller has overseen multiple neuroscience construction projects, OR projects and Women’s Services renovations.

Dan moved to his role as CEO of TMCA after 13 years with Hospital Corporation of America (HCA) serving in various administrative roles. He received his Bachelor of Science in Human and Organizational Development from Vanderbilt University in Nashville, Tennessee and his Master of Science in Health Administration from Virginia Commonwealth University in Richmond, Virginia. Dan is a graduate of the HCA’s COO Development Program.

Dan is a Fellow in the American College of Healthcare Executives (FACHE) and appointed member of city of Englewood’s’ Alliance for Economic Development, HSS Inc. Board of Directors and the Denver Southeast Rotary. Dan is married and has two children.


Simpson, Ryan-72dpi

Ryan Simpson, FACHE
Chief Operating Officer

Ryan Simpson has been in hospital leadership roles for 20 years and is currently Chief Operating Officer for HCA/HealthONE’s, Medical Center of Aurora; including its Main Campus, North Campus, and Centennial Medical Plaza. Having started this role in June 2011, he is responsible for the daily operations of each facility.

Prior to joining HealthONE, Ryan served in HCA’s Nashville market as Chief Operating Officer for The Sarah Cannon Cancer Center and TriStar Oncology Services. Prior to that, he was with Middle Tennessee Medical Center (MTMC) in the chief operations role. In addition to general hospital operations at MTMC, he led the planning, programming, and construction of a $267 million replacement facility. Prior to joining MTMC, he was with Baptist Health System of East Tennessee in Knoxville for nine years. 

Upon graduating with a B.S. in Finance and Marketing from Birmingham-Southern College he spent two years in the banking industry in Birmingham, Alabama before attending graduate school. Ryan received his MBA and a Master's degree in Health Administration from the University of Alabama at Birmingham. He is a Fellow in the American College of Healthcare Executives (FACHE) and is currently chairman of the Aurora (CO) Chamber of Commerce. Ryan and his wife Johanna have two children and reside in Highlands Ranch, CO.  


Rossitto, Erica-72dpi

Erica Rossitto, MBA/HCM, BSN, RN, NEA-BC
Chief Nursing Officer

Erica Rossitto is currently serving as the Chief Nursing Officer for The Medical Center of Aurora, a role she has held since November of 2013. She is responsible for the nursing operations at the Main Campus, Behavioral Health Campus and Centennial Medical Plaza.

Erica has been a nurse for nearly 17 years. Her career with HCA began as a staff nurse at Swedish Medical Center, where she spent 8 years, eventually progressing to the role of Associate Chief Nursing Officer. In 2007, Erica graduated from HCA’s CNO Executive Development Program, and was promoted to the role of Chief Nursing Officer at North Suburban Medical Center. She held that position for 6 years prior to joining the team at The Medical Center of Aurora.

Originally from Louisiana, she received her Bachelor's Degree in Nursing from McNeese State University, with a minor in Psychology. Erica also has her MBA with a focus in Healthcare Management, and recently earned her Nurse Executive Advanced Board Certification from the ANCC. She is currently serving as Secretary of the Board for the Colorado Organization of Nurse Leaders. Erica was nominated by her team in 2016 for the Nightingale Award, and proudly celebrated her 16 year anniversary with HCA this past June. Erica and her husband, Josh, have two sons and reside in Southeast Aurora.


Dehaven, Bryce-72dpi

Bryce Dehaven, CPA
Chief Financial Officer

Bryce Dehaven has nearly 30 years of financial leadership experience, with over 25 of those years in the HCA healthcare system. Before joining the Medical Center of Aurora in July 2013, Bryce served as CFO at 3 other HCA Facilities in Independence, MI, San Jose, CA, and most recently at Orange Park Medical Center (OPMC), a 297-bed facility in Jacksonville, FL.

Bryce completed his undergraduate studies at the University of Arizona, and received his Master in Business Administration from the University of Colorado at Denver. He previously served on the American Cancer Society Board of Directors, and is currently a member of the Texas State Society of CPA’s. Locally, Bryce serves on the Aurora Health Access Board of Directors, a regional group focused on improving access to healthcare within the community of Aurora. 

Bryce has extensive experience in the field of behavioral health, most prominently as the Co-Founder of Psychiatric Solutions, Inc. Bryce and his wife, Susan have 3 children and reside in Greenwood Village, CO.


McCallister, Dianne-72dpi

Dianne McCallister, MD, MBA
Chief Medical Officer

Dr. McCallister is a board certified Internal Medicine physician, with over 25 years of clinical experience. She received her M.D. at the University of Colorado and an MBA from Daniel’s College of Business at the University of Denver. She is a certified Patient Safety Officer, a Green Belt in Six Sigma Process Improvement Methodology and is certified as a facilitator of Rapid Improvement Process. With a family full of nurses and physicians, she possesses a strong belief that medicine is best practiced as a team sport, and approaches quality and safety initiatives with this in mind.

Dr. McCallister has been at The Medical Center of Aurora since May 2013 as the Chief Medical Officer and Patient Safety Officer. She initiated a comprehensive Physician Wellbeing and Engagement program at the hospital, which culminated in the facility being the first of four hospitals in the country to receive the Medicus Integra© Award from the Coalition for Physician Wellbeing. During her tenure, the Physician Satisfaction has had double digit increases in all metrics.

Prior to her time at Aurora, Dr. McCallister served at Centura Health, where she served as Chief Medical Officer and VP Patient Safety and Quality Systems for Porter Adventist Hospital where she pioneered a Physician Wellbeing program that again produced across the board increases in physician satisfaction and engagement.  Prior to joining Porter in 2005, she was the Medical Director and President of the Medical Staff for Parker Adventist Hospital, which she helped to open, and served as a PHO Medical Director while she practiced as a partner in large Internal Medicine groups in the Denver area. She served as Chief Medical Resident at Presbyterian/St. Luke’s Hospital and as an instructor in Internal Medicine for University of Colorado School of Medicine.

Dr. McCallister is a national expert in Physician Wellbeing, and was the co-founder of the Coalition for Physician Well-Being, a group that endeavors to support, engage and inspire physicians across the country, as well as educate institutions on structures to support Physician Well-Being. She leads the Development and Research Group that created the Medicus Integra© Award and serves on the Executive Committee for the Coalition. Dr. McCallister speaks nationally on structures and programs to support and improve Physician Wellbeing and Engagement, as well as on hospital recovery from mass-casualty events. She is on the National Physician Advisory Board for Med News Plus, an electronic Newsletter/CME Vehicle. 

She shares her passion for healthcare through her service on the board of Christian Living Communities and on the Board of a local PHO, HealthONE Physician Partners. Dr. McCallister was regular contributor to the 11:00am newscast on Denver Channel 7, where she has served as their medical expert for five years prior to starting at TMCA. In addition, she has served as faculty of the AMA’s Media in Medicine conferences, and as an Editor of the Journal for Healthcare Communications.

Dianne and her husband, Tom, live in the Denver Tech Center, and are an active part of the community. Dianne is involved in the local community as President of the Home Owner’s Association in her neighborhood. In her free time, she enjoys kayaking, reading and time with her family.


Woods, Hallie

Hallie Woods, MBA
Associate Chief Operating Officer

Hallie Woods joined The Medical Center of Aurora in April 2016 as the Associate Chief Operating Officer. This position is part of HCA’s Chief Operating Officer Development Program. At The Medical Center of Aurora, Hallie is responsible for the departments of Radiology, Pharmacy, Therapies, and Plant Operations.

Hallie’s past experience includes Director of Radiology, Radiation Oncology, and Cardiovascular Services at HealthONE Hospitals Presbyterian/St. Luke’s Medical Center and Rocky Mountain Hospital for Children. Hallie earned her Master's degree in Health Administration from University of Colorado and a B.A. in Journalism from Colorado State University.

Hallie is a Colorado native and enjoys golf, cooking, and exploring the outdoors. Hallie and her husband, Jason, reside in Southeast Denver with their son, Parker. 


Mencini, Brandon-72DPI

Brandon Mencini, MHA
Vice President, Business Development
& Strategic Planning

Brandon Mencini joined The Medical Center of Aurora as Vice President of Business Development in June 2016. In this role, Brandon has oversight over the comprehensive growth agenda for all of The Medical Center of Aurora's campuses; including strategic planning, real estate, marketing, physician relations, and community relations. Prior to this role, Brandon worked in various business development, strategic planning, and operations roles locally with both HCA/HealthONE and Centura Health. Brandon’s passion for healthcare originated early in his career when he started at the ground-level working as an EMT at a Level I Trauma Center.

Brandon’s passion for healthcare extends beyond the hospital walls and well within the community. Brandon served as the chairman of the Board of Directors for Arapahoe House, Colorado’s largest provider of addiction treatment. In addition, Brandon sits on the Project Angel Heart Board of Directors, Metro Denver Economic Development Corporation Board of Governors, and volunteers with the Leukemia & Lymphoma Society.

Brandon has been recognized with various awards and honors including a nomination for Leukemia & Lymphoma Society’s “Man of the Year Award” in 2016,  Denver Business Journal’s annual “40 Under 40” award in 2015, and a feature in Denver Business Journal’s “Making Their Mark” series in 2013.

Brandon received a Bachelor of Arts Degree in Psychology from the University of Colorado and his Master's degree in Health Administration from Webster University. Brandon and his wife, Michelle, reside in Littleton with their children, Nicolas and Gianna. In his off-time Brandon can be found playing competitive bocce, cooking in barbeque competitions, and skiing.


Artis, Eric-72dpi

Eric D. Artis, M.Ed, PHR
Vice President, Human Resources

Eric Artis has over 20 years of Human Resources experience. His background includes experience in strategic planning, leadership development and all aspects of HR (benefits, recruitment, workers’ compensation, employee relations and employment law).

Eric served in the United States Air Force for 10 years and worked for the Wyoming Department of Commerce and the Wyoming Professional Teachers Standards Board before relocating to Colorado.

Prior to coming to The Medical Center of Aurora in 2008, Eric served as the Vice President of Human Resources for Presbyterian/St. Luke’s Medical Center from 2004 to 2008

Eric has earned the Professional Human Resource (PHR) certification from the Society for Human Resource Management (SHRM), a Bachelor of Science degree in Business Administration, a Master’s degree in Business/Human Resources from Colorado State University and completing his PhD in Industrial and Organizational Psychology.  

Eric and his wife, Kisha, give back to their community by mentoring youth as part of the Kappa Alpha Psi, Kappa League & Guide Right Program, as well as supporting personnel on Buckley Air Force Base transitioning out of the military.


Butts, Leslie-72dpi

Leslie Butts, MHA
Administrative Fellow

Leslie Butts is the Administrative Fellow for The Medical Center of Aurora and has been with TMCA since July of 2015. Leslie received her Master’s degree in Healthcare Administration from the University of Alabama at Birmingham and undergraduate degree from Trinity University.

Prior to joining the team at The Medical Center of Aurora, Leslie was a graduate intern at St. Vincent’s Health System and The University of Colorado Hospital. Leslie currently oversees Food and Nutrition Services, Environmental Services, the Pre-authorization program and the Chiari program.

Leslie is originally from Arizona and is a former collegiate swimmer. She enjoys hiking, camping, skiing and volunteering as a mentor through Big Brothers Big Sisters. Leslie is currently training for her first half-ironman.