About Us

Doug Mitchell, MD, MBA

Co-Founder and Chief Executive Officer

Dr. Doug Mitchell is a physician pioneer who possesses a strong business and clinical acumen. Doug sets the strategic direction for Adfinitas Health’s hospitalist leaders, practitioners, and operational teams.

Doug’s leadership, coupled with his drive towards rigorous performance standards, has helped to save the firm’s hospital and post-acute partners millions of dollars. As a leader who creates innovative quality initiatives and embraced value-based care from the company’s inception, he has been instrumental in improving core measures, quality metrics, and patient satisfaction results for clients.

Doug was among the first to expand the role of hospitalists to include surgical and specialty medicine and to launch a training program for Advanced Practice Providers. He is dedicated to providing a work-life balance for the professionals he hires, and to creating an environment in which they feel fulfilled by their work. This is reflected in the company’s “culture of yes.” Introduced early on, this remains a strongly held core value that focuses on building deep interpersonal connections amongst the care team and being highly responsive to patients and clients while providing quality medical care.

A board-certified internist, Doug has practiced hospitalist medicine since 1998. He completed his medical training at the Uniformed Services University of the Health Sciences and his residency in Internal Medicine at Walter Reed Medical Center. After seven years of public medical service in the Indian Health Service, he became a member of the medical staff of Anne Arundel Medical Center, where he was named the first head of its hospitalist service. As a physician who was long interested in becoming a healthcare administrator, he also earned an MBA from Auburn University. Doug’s former leadership positions include serving as medical staff president at Anne Arundel Medical Center from 2009 to 2012.

Hung Davis, MD, CMD, WCC

Co-Founder and Chief Medical Officer

In 2007, Doug Mitchell and I co-founded Maryland Inpatient Care Specialists (MDICS), later renamed Physicians Inpatient Care Specialists. On the eve of its 10th Anniversary, the company unveiled a new name and identity—Adfinitas Health.

At Adfinitas Health, I’d initially directed the post-acute services (PAS) division as its CEO, transitioned to the company’s CMO position in 2019. I’m a board-certified Internist as well as certified medical director (CMD), who has had two decades of clinical-leadership experience—both in acute-hospital and acute/subacute-rehab medicine. Preceding my medical career, having served three years of active duty in the U.S. Army, I have benefitted from the military experience representing as an impetus, a genesis, for my leadership career—principally growing future leaders for the medical field.

Over the years, Adfinitas Health has grown from providing acute-hospital medicine services at a single facility to becoming the largest private hospitalist company based in Maryland, serving more than 60 hospitals and post-acute care centers across midwestern and eastern states. We provide care in a growing array of specialties and settings, including observational units, transitional care units, ICUs, inpatient and outpatient rehabilitation, and inpatient pediatrics.

Timothy M. Capstack, MD, FACP, SFHM

Partner and Director of Clinical Integration

Dr. Timothy Capstack, partner and director of clinical integration, leads Adfinitas Health’s efforts to advance clinical integration and training of nurse practitioners and physician assistants across acute and post-acute services. Over the years he also has provided site and regional level leadership to several of our hospital medicine programs, providing oversight of clinical quality assurance and improvement and education of students and recent graduates, and works closely with other program directors, consultants, and hospital administration.

Tim was the lead author for the 2016 study “A Comparison of Conventional and Expanded Physician Assistant Staffing Models at a Community Hospital,” published in the Journal of Clinical Outcomes Management, which demonstrated the efficacy and safety of a hospital staffing model that employed a high ratio of PAs to physicians. Tim is a Senior Fellow in Hospital Medicine and a Fellow in the American College of Physicians.

Tim completed his medical degree from Washington University School of Medicine and his residency training in internal medicine at Barnes-Jewish Hospital. He is board certified in internal medicine.

Chang Choi, MD, FHM

Partner and Regional Medical Director

Dr. Chang Choi, Partner and Regional Medical Director, leads clinical operations at several Adfinitas Health hospital facilities. He initially joined the company as Director of the Hospitalist Program. During his tenure with Adfinitas Health, he has served on numerous committees at the hospital, including the Medical Executive Committee, Joint Quality Improvement and Safety committee, and MHAC. He has also served as the Medical Director of Informatics and served as the physician champion for building and implementing a new EHR system called Meditech Advanced Technology.

Prior to joining Adfinitas Health Chang served as a hospitalist at Anne Arundel Medical Center for several years.

Chang earned a BS in biophysics from Johns Hopkins University. He completed his medical training at the University of Maryland School of Medicine and his residency in internal medicine at the University of North Carolina Memorial Hospital in Chapel Hill. He is board-certified in internal medicine.

Steven Hamlette, MD, SFHM, FACP

Partner and Regional Medical Director

Dr. Steven Hamlette, Partner and Regional Medical Director, oversees clinical operations for several Adfinitas Health acute care facilities. Steven began his medical career as a National Health Service Corps physician, working as an internist in an under-served area of Somerset County, Maryland. After developing a passion for hospital medicine, he partnered with other physicians to form a private hospital medicine group on the Maryland Eastern Shore. He subsequently joined the team at Adfinitas Health after meeting and being impressed with its founders.

He is board certified in hospital medicine by the American Board of Internal Medicine and the National Board of Physicians and Surgeons.

Steven earned a BS in Chemistry and completed his medical training at Howard University. He completed his residency in Internal Medicine at The Johns Hopkins University/Sinai Hospital. As an attending physician, he also completed the Business of Medicine Graduate Program at the Johns Hopkins Carey Business School.

Ivelisse Michel, MD

Partner and Medical Director

Dr. Ivelisse (“Ivy”) Michel, Partner and Medical Director, leads one of Adfinitas Health’s hospital sites. As Medical Director, she oversees day-to-day management of clinical and management staff, and works closely with hospital leadership to ensure that their priorities and objectives are met. One of her many accomplishments at the hospital has been implementing an effective transitions of care program to reduce readmissions.

Ivy completed her medical training at the Medical College of Wisconsin and her family medicine residency at Bayfront Medical Center in St. Petersburg, Florida, where she was chief resident. Ivy is board certified in family medicine.

Hollie Hurner, PA-C

Partner and Director

Hollie Hurner, partner and director, leads one of Adfinitas Health’s rural sites in southern Maryland. Her role includes managing the day to day operations of the hospitalist group, serving on hospital committees and working closely with the hospital administration. She also serves as director of informatics. Hollie joined Adfinitas Health in March 2009 as a physician assistant at Calvert Memorial Hospital. She served as lead physician assistant at Calvert and has filled staffing needs at several of our other hospitals prior to assuming her current role.

Hollie served in the United States Army as a medical specialist and attained the rank of Staff Sergeant. NCCPA Certified, she actively serves on several of their committees. She also is a member of the American Academy of Physician Assistants and the Society of Hospital Medicine.

Hollie earned an AA degree from Chaminade University, Honolulu, Hawaii and a BS from Florida Southern College. She also holds a master’s degree in Physician Assistant Studies from Methodist University.

Maria Hess

Vice President and Chief Operating Officer for Post-Acute Services

Maria Hess, Vice President and Chief Operating Officer for Post-Acute Services, is responsible for the company’s financial and clinical operations in post-acute care. Maria hires physician and APP staff for our post-acute care partners, and ensures compliance with company and center-specific metrics to deliver high-quality post-acute care and reduce readmissions. She meets with our post-acute care clients on a quarterly basis.

Maria joined Adfinitas Health with 30 years of experience as a licensed RN and 16 years of experience working in sales and marketing for a national rehabilitation and long-term care organization, where she managed several hospital accounts. She began her career as an ICU nurse and then spent several years at University of Maryland Medical Center in Shock Trauma as the Assistant Director of Quality, working in quality and risk management and the Patient Representative Program, where she developed policies and procedures, managed programs, and educated providers. Maria was on the board and served as both president elect and president of the Maryland Association of Healthcare Quality for two years.

Maria earned an RN degree from the Washington School of Nursing and an undergraduate degree from the University of Maryland Baltimore Campus.

Ensley Fleming

Chief Operating Officer for Hospital Medicine Services

Ensley Fleming, Chief Operating Officer, plans and manages the administrative, personnel, financial, and operational activities of all hospital medicine programs for the company. She has over 10 years of experience in healthcare through a range of roles focused on operations, financial planning, and strategic and program development. Prior to joining Adfinitas Health, she held consulting and financial roles with ECG Management Consultants and Johns Hopkins School of Medicine. She is a member of ACHE and HFMA.

Ensley holds a master of finance degree from Johns Hopkins University and graduated cum laude with a bachelor of science degree in health services administration from Auburn University.

Louis O’Boyle, DO, FACP, SFHM

Partner and Regional Medical Director

Dr. Louis O’Boyle, Partner and Regional Medical Director, manages four hospital and several post-acute programs across northeastern Pennsylvania. Lou founded Advanced Inpatient Medicine in 2006, which was acquired by Adfinitas Health in January 2018. He has over 25 years of experience in internal medicine and hospital medicine. As Regional Medical Director, he oversees day-to-day management of clinical and management staff, and works closely with hospital leadership to ensure that their priorities and objectives are met.

In 2015, Lou was only the fourth doctor in the U.S. to earn the Society of Hospital Medicine’s Certificate of Leadership in Hospital Medicine for making a significant contribution to hospital medicine with his research project, “A Multidisciplinary, Multi-interventional Approach to Reducing Readmissions in the Rural Setting.”

He attended the University of Scranton and graduated from Philadelphia College of Osteopathic Medicine in 1990.

Karen Cousins DO, CMD

Stephanie Stewart

Chief Human Resources Officer

Stephanie Stewart, Chief Human Resource Officer, provides strategic oversite and contributions in the areas of recruiting, retention, credentialing, benefits, organizational design, performance management and contract review. She is a seasoned human resources executive with over 20 years of leadership experience spanning private equity-based startups and non-profit national healthcare organizations.

As the vice president of human resources at American Physician Partners, she spearheaded HR operations, aligning them with overarching business strategies to facilitate growth and cultivate a culture of continuous improvement. Stephanie’s strategic acumen has driven remarkable results, with a 72% increase in contracts and a remarkable 94% revenue growth in one year. Her comprehensive skill set encompasses HRIS development, employee relations, compensation, and benefits, making her an indispensable asset in navigating complex mergers and acquisitions, compliance, and change management.

With a strong focus on employee development and engagement, Stephanie is an architect of high-performance HR practices. Her tenure at Ascension Health further underscores her
expertise, where she successfully led benefit standardization efforts, resulting in $19 million in annual savings.

As a transformative leader, Stephanie’s contributions have extended to local and national shared service centers, optimizing HR functions, benefits, and compensation, all while reducing redundancy and maximizing efficiency. Stephanie’s dedication to innovation, operational excellence, and her commitment to fostering a supportive work environment make her an outstanding human resources executive.

Stephanie holds a bachelor’s degree of business from the University of Tennessee Knoxville.

Tim Delbrugge, CPA

Vice President and Chief Financial Officer

Tim Delbrugge, CPA, Vice President and Chief Financial Officer, is responsible for the overall financial health of the company, with a particular focus on ensuring that the finance organization supports the company’s growth strategy. He oversees all aspects of corporate financial functions – including tax, treasury, revenue cycle management, accounts payable, financial planning & reporting and information technology (IT) management.

Tim has over 32 years of experience in Finance and Accounting and has led Human Resources, IT and Logistics functions in his various roles during his career. His healthcare experience includes roles as the CFO at Brook Lane Health Services, Executive Director, Finance at Meritus Health and Chief Accounting Office at Helix Health where he was a key contributor to the merger with Washington Hospital Center to form what is now MedStar Health.

Tim started his career at PriceWaterhouse where he spent nine and half years. His other roles included CFO at Welocalize, interim CFO at the SEED School of Maryland and over 9 years at W.R. Grace where he held the positions of Vice President of Internal Audit, Vice President/Controller and CFO of the Europe, Middle East, Africa region where he spent over three and a half years based in Germany.

Tim graduated cum laude with a Bachelor of Science in Business Administration with concentrations in Finance and Accounting from Bryant University.

Karen Ann Millard, FACMPE

Director of Revenue Cycle Management

Karen Millard, Director of Revenue Cycle Management is responsible for overseeing the revenue cycle process from charge capture through collection of patient service revenue and the corporate compliance program for Adfinitas Health. She has over 27 years in leadership in revenue cycle with a wide range of experience in receivables management, workflow development, system design & implementation, corporate compliance, quality program participation and customer satisfaction strategies.

Prior to joining Adfinitas Health, Karen has held Revenue Cycle Director positions with Frederick Health, Rochester Regional Health System and Arnot Health. She is a fellow (FACMPE) in the American College of Medical Practice Executives through MGMA and is an active board member of Maryland MGMA.

Karen earned her Bachelor of Science degree in Business Administration from SUNY Empire.