Implemented or not implemented? Process evaluation of the school-based obesity prevention program DOiT and...

Area of Science:

• Public Health
• Intervention Science
• Adolescent Health

Background:

• Childhood obesity is a significant public health concern.
• Effective interventions are crucial for preventing and managing obesity in adolescents.
• The Dutch Obesity Intervention in Teenagers (DOiT) program aimed to address this issue in prevocational education settings.

Purpose of the Study:

• To evaluate the implementation fidelity and effectiveness of the DOiT program.
• To assess process indicators including recruitment, reach, dosage, fidelity, satisfaction, effectiveness, and continuation.
• To explore the relationship between program implementation and its effectiveness.

Main Methods:

• A multi-site study conducted in 20 prevocational education schools in the Netherlands.
• Data collected via teacher questionnaires (n=110) and adolescent questionnaires/adiposity measures (n=938).
• Multi-level confirmatory factor analyses used to develop an implementation index score.

Main Results:

• Program implementation varied, with high success in school support (93%) but low completion of activities like closure meetings (9%).
• Fidelity to the teacher manual ranged from 85% to 26%, and lesson delivery decreased significantly over time (74% to 18%).
• Teachers reported general satisfaction, yet overall implementation was lower than anticipated, particularly later in the program.

Conclusions:

• The DOiT program experienced implementation challenges, especially concerning dosage and fidelity towards the end.
• Teacher satisfaction was noted, but program reach and consistency require improvement.
• Preliminary evidence suggests a positive association between implementation index scores and program effectiveness, necessitating further validation.