Does establishing fidelity of treatment help in understanding treatment efficacy? Comment on Bellg et al. (2004).

Comments on the article by Bellg et al (see record 2004-18051-001). To test the effects of a behavioral change on specific health outcomes, the Behavior Change Consortium insists on strict adherence to fidelity at 5 steps in behavioral trials: study design, provider training, treatment delivery, treatment receipt, and enactment of treatment skills. The authors argue that the demand for fidelity at every step ignores 2 critical sets of factors: (a) there are few theoretically grounded empirical studies of the processes involved in successful transitions in this sequence and (b) trials with perfect fidelity absent a theoretical model of transitions will produce evidence for interventions that lack a conceptual basis for adaptation to differences among diseases, treatments, patients, practitioners, medical institutions, and cultures and that therefore cannot be implemented in clinical practice.