Strategies for supporting intervention fidelity in the rehabilitation therapy in older acute heart failure patients (REHAB-HF) trial.

Introduction: Acute decompensated heart failure (ADHF) is the leading cause of hospitalization in older adults. Rehabilitation Therapy in Older Acute Heart Failure Patients (REHAB-HF) trial is a multi-site clinical trial to determine if physical rehabilitation intervention in older patients with ADHF improves physical function and reduces rehospitalizations. The REHAB-HF intervention aims to improve functional performance utilizing reproducible and progressive exercises that are individually tailored to the patient's physiological and physical capabilities. Fidelity of the intervention is essential to the trial's integrity and success. Maintaining fidelity is challenged by the complex, multi-domain design of the intervention implemented across multiple sites and delivered to an older, heterogeneous participant pool with severe underlying disease and multi-morbidity.

Methods/design: Given the dynamic nature of the REHAB-HF intervention, rigorous fidelity strategies were formulated. In this paper we summarize the specific strategies that REHAB-HF is using to meet the National Institutes of Health (NIH) Behavior Change Consortium Treatment Fidelity Workgroup recommendations in 5 key areas: 1) ensuring the intervention dose is consistent across participants, 2) standardizing interventionist training, 3) monitoring intervention delivery, 4) evaluating participants' understanding of information provided, and 5) ensuring that participants use the skills taught in the intervention.

Discussion: Effective intervention fidelity strategies are essential to the reliability and validity of physical function intervention trials. The REHAB-HF trial has developed comprehensive, specific strategies to ensure intervention fidelity despite a challenging study population and a complex intervention to meet NIH recommendations. This experience provides a strong working model for future physical function intervention trials.