Incorporating intervention fidelity components into randomized controlled trials promoting exercise adherence in heart failure patients.

Intervention fidelity (IF) in behavioral interventions is complicated by their dynamic and interactive nature. Translation of the outcomes to practice may be diminished by lack of fidelity. The purpose of this paper is to describe a systematic, evidence-based IF approach in a complex, multicomponent behavioral change study. The National Institutes of Health-funded randomized controlled trial was designed to evaluate the effect of an adherence to exercise intervention. Two hundred forty-six heart failure patients from two sites were enrolled. This description of the study-specific standardized protocol, the data collection methods used, findings from the plan, and the discussion of the successes and challenges contributes to the advancement of IF implementation science.