Implementation fidelity in adolescent family-based prevention programs: relationship to family engagement

Reliability and validity of intervention studies are impossible without adequate program fidel-ity, as it ensures that the intervention was implemented as designed and allows for accu-rate conclusions about effectiveness (Bellg AJ, Borrelli B, Resnick B et al. Enhancing treatment fidelity in health behavior change studies: best practices and recommendations from the NIH behavior change consortium. Health Psychol 2004; 23: 443–51). This study examines the re-lation between program fidelity with family en-gagement (i.e. satisfaction and participation) in family-based prevention programs for adoles-cent alcohol, tobacco or other drug use. Families (n 5 381) were those with an 11- to 12-year-old child enrolled in Kaiser Permanente in the San Francisco area. Families participated in one o