Promoting intervention fidelity - Conceptual issues, methods, and preliminary results from the EARLY ALLIANCE prevention trial

Fidelity refers to the demonstration that an experimental manipulation is c onducted as planned. In outcome research, an intervention call be said to s atisfy fidelity requirements if it can be shown that each of its components is delivered in a comparable manner to all participants and is true to the theory and goals underlying the research. Demonstrating the fidelity of an intervention is a key methodologic requirement of any sound prevention tri al. This paper summarizes key conceptual and methodologic issues associated with intervention fidelity, and describes the steps taken to promote fidel ity in EARLY ALLIANCE, a large-scale prevention trial currently testing the effectiveness of family, peer, and school interventions to promote compete nce and reduce risk for conduct disorder, substance abuse, and school failu re. The paper presents preliminary results (Trial Year 1) that demonstrate content and process fidelity for two of these interventions, and discusses how the EARLY ALLIANCE methodology may be generalized to address fidelity i ssues in ether prevention studies.