Stefan is a seasoned public health professional and academic. Since 2013, Dr. Keller has worked for the Hawaii State Department of Public Health as an evaluation specialist in the Adult Mental Health Division. Prior to that, he was assistant and associate professor in public health sciences and epidemiology, University of Hawaii (2005-2012); associate member of the Cancer Research Center of Hawaii (2006-2010); assistant professor/senior researcher at the University of Marburg, Germany, Department of Medical Psychology (1993-2005); and post-doctoral fellow at the Cancer Prevention Research Center, University of Rhode Island. Other notable positions and activities include membership on the Board of Directors for Hawaii's Community Health Outreach Work, a statewide needle exchange program for injection drug users with a focus on HIV and hepatitis prevention; former membership on the Community Advisory Board which brought together members of community organizations and academia in Public Health at U of HI; involvement in Coalition for Tobacco-free Hawaii and the Hawaii Comprehensive Cancer Coalition.
Stefan has made notable contributions to research, particularly his evaluation of the Transtheoretical Model as applied to various behavioral health problems (e.g., smoking, binge drinking). He is highly committed to creating synergies between the community and academia and is a conscientious teacher and mentor. He has published 67 peer-reviewed articles, many in leading journals in our field (e.g., Preventive Medicine, Patient Education & Counseling, Spine), 23 book chapters, and two edited books. Dr. Keller has taught undergraduate and graduate students, has used a wide range of approaches, and has taught students in diverse health professions, including public health, psychology, medicine and physical therapy. He also has led workshops on motivational interviewing and counseling designed to improve the health promotion efforts of various health professionals, including physicians, nurses, nutritionists, drug counselors, and psychologists.