An intervention that appears effective in an RCT may not translate into effectiveness under real-world conditions. Health behavior researchers too often accept a diffusion model, which relies on absorption and implementation of intervention techniques by health behavior specialists with the knowledge and time to successfully move the strategy through the last translational transition from clinical trials to practice implementation.32 In fact, most behavior change interventions that are tested in RCTs will never be adopted into health-care settings. Four barriers underlie this failure. First, although some health-care settings may include health behavior specialists, most do not, leaving the task of motivating patients to change their behavior to busy physicians, nurses, and physician assistants. Second, many behavioral interventions are time, labor, and cost intensive and therefore are unfeasible within most health-care systems. Third, RCTs often are only modestly effective, and moderators/mediators rarely are identified, leaving clinicians and researchers feeling less confident in their applicability to the clinical setting. Fourth, RCTs typically exclude patients who have comorbid medical or psychologic disorders or who do not demonstrate high levels of adherence during a run-in period, thereby failing to test the intervention on a complex combination of patients who comprise the patient population in many clinical settings.