Enhancing Treatment Fidelity in Health Behavior Change Studies: Best Practices and Recommendations From the NIH Behavior Change Consortium Albert J. Bellg Appleton Heart Institute Belinda Borrelli Brown Medical School Barbara Resnick University of Maryland Jacki Hecht Brown Medical School Daryl Sharp Minicucci University of Rochester Marcia Ory National Institutes of Health Gbenga Ogedegbe Cornell University Denise Orwig University of Maryland Denise Ernst University of New Mexico Susan Czajkowski National Institutes of Health (For the Treatment Fidelity Workgroup of the NIH Behavior Change Consortium) Treatment fidelity refers to the methodological strategies used to monitor and enhance the reliability and validity of behavioral interventions. This article describes a multisite effort by the Treatment Fidelity Workgroup of the National Institutes of Health Behavior Change Consortium (BCC) to identify treatment fidelity concepts and strategies in health behavior intervention research. The work group reviewed treatment fidelity practices in the research literature, identified techniques used within the BCC, and developed recommendations for incorporating these practices more consistently. The recommendations cover study design, provider training, treatment delivery, treatment receipt, and enactment of treatment skills. Funding agencies, reviewers, and journal editors are encouraged to make treatment fidelity a standard part of the conduct and evaluation of health behavior intervention research. Key words: treatment fidelity, health behavior, translational research, reliability, validity Treatment fidelity refers to the methodological strategies used to monitor and enhance the reliability and validity of behavioral inter- ventions. It also refers to the methodological practices used to ensure that a research study reliably and validly tests a clinical intervention. Although some strategies to enhance treatment fidelity in research may be quite familiar (e.g., the use of treatment manuals, videotape monitoring of therapist adherence to research protocols, and testing subject acquisition of treatment skills), there is inconsistency in their use, particularly in health behavior intervention research. Method- ological procedures for preserving internal validity and enhancing external validity in studies, though critical to the interpretation of findings, are not emphasized in research-training curricula, and their relative lack of perceived importance is also evidenced by the scant reporting of treatment fidelity practices in journal articles. By com- parison, procedures for evaluating the reliability and validity of ques- tionnaires and other measurement instruments are well understood. Our purpose in this article is to provide a useful conceptualization of treatment fidelity, describe specific treatment fidelity strategies, and offer recommendations for incorporating treatment fidelity practices in health behavior intervention research. We believe that adopting these practices will contribute to the continued development of inno- vative, credible, and clinically applicable health behavior interven- tions and programs. The concept of treatment fidelity has evolved over time. Al- though treatment fidelity was mentioned in a few social and behavioral studies in the late 1970s and early 1980s (e.g., Peterson, Homer, & Wonderlich, 1982; Quay, 1977), Moncher and Prinz’s Albert J. Bellg, Appleton Cardiology Associates, Appleton Heart Insti- tute, Appleton, Wisconsin; Belinda Borrelli and Jacki Hecht, Center for Behavioral and Preventive Medicine, Brown Medical School; Barbara Resnick, School of Nursing, University of Maryland; Daryl Sharp Mi- nicucci, School of Nursing, University of Rochester; Marcia Ory, National Institute on Aging, National Institutes of Health (NIH); Gbenga Ogedegbe, Weill Medical College, Cornell University; Denise Orwig, School of Medicine, University of Maryland; Denise Ernst, Department of Family Practice, University of New Mexico; Susan Czajkowski, National Heart, Lung, and Blood Institute (NHLBI), NIH. Marcia Ory is now at the Department of Social and Behavioral Health, School of Rural Public Health, Texas A&M University. Gbenga Ogedegbe is now at the Department of Medicine, College of Physicians and Surgeons, Columbia University. Senior authorship is shared equally between Albert J. Bellg and Belinda Borrelli. Funding for this multisite project was provided by NIH/NHLBI Grant R01 HL62165 to Belinda Borrelli (principal investigator). We would like to thank all the principal investigators and staff members of the Behavior Change Consortium who contributed to this article by identifying treatment fidelity practices used in their studies. Correspondence concerning this article should be addressed to Albert J. Bellg, Appleton Heart Institute, 1818 North Meade Street, Appleton, WI 54911. E-mail: albert.bellg@thedacare.org Health Psychology Copyright 2004 by the American Psychological Association 2004, Vol. 23, No. 5, 443– 451 0278-6133/04/$12.00 DOI: 10.1037/0278-6133.23.5.443 443