Fidelity of implementation in project towards no drug abuse (TND): A comparison of classroom teachers and program specialists

This paper presents the results of an effectiveness trial of Project Towards No Drug Abuse [TND], in which we compared program delivery by regular classroom teachers and program specialists within the same high schools. Within 18 schools that were randomly assigned to the program or control conditions, health classrooms were assigned to program delivery by teachers or (outside) specialists. Classroom sessions were observed by pairs of observers to assess three domains of implementation fidelity: adherence, classroom process, and perceived student acceptance of the program. Pre- and immediate posttest survey data were collected from 2331 students. Of the four composite indexes of implementation fidelity that were examined, only one (quality of delivery) showed a difference between specialists and teachers, with marginally higher ratings of specialists (p < .10). Both teachers and program specialists achieved effects on three of the five immediate outcome measures, including program-specific knowledge, addiction concern, and social self-control. Students' posttest ratings of the program overall and the quality of program delivery failed to reveal differences between the teacher- and specialist-led classrooms. These results suggest that motivated, trained classroom teachers can implement evidence-based prevention programs with fidelity and achieve immediate effects.