Assessment of Delivery and Receipt of a Complex School-Based Smoking Intervention: A Systematic Quantitative Process Evaluation

Comprehensive school tobacco policies have the potential to reduce smoking in vocational education where smoking is widespread. Assessment of the implementation process is important to understand whether and how complex interventions work, yet many studies do not measure receipt among the target group. We conducted a quantitative process evaluation of a newly developed smoking intervention in Danish vocational education to (1) operationalize measures of delivery and receipt, (2) investigate the extent to which the intervention was delivered and received, and (3) analyze whether this differed across school settings. We used questionnaire data collected 4–5 months after baseline among students ( N = 644), teachers ( N = 54), and principals ( N = 11) from 8 intervention schools to operationalize implementation at the school level (delivery; content, quality, and fidelity) and student level (receipt; participation, responsiveness, exposure, and individual-level implementation). We calculated means and compared levels across school settings using stratified analysis and mixed models. The total intervention was delivered by a mean of 76% according to how it was intended and received by a mean of 36% across all students. Relatively low means of participation and responsiveness indicated challenges to reach the students with the intervention components, and delivery and receipt varied between school settings. This study highlights the challenge of reaching the intended target group in complex health behavior interventions even when reaching relatively high levels of fidelity. Further studies using the operationalized measures can give insight into the ‘black box’ of the intervention and strengthen future programs targeting smoking in vocational education.