Psychometric characteristics of process evaluation measures for a rural school-based childhood obesity prevention study: Louisiana Health

Abstract

Purpose: To evaluate the implementation of intervention components of the Louisiana Health study, which was a multicomponent childhood obesity prevention program conducted in rural schools.

Design: Content analysis.

Setting: Process evaluation assessed implementation in classrooms, gym classes, and cafeterias.

Subjects: Classroom teachers (n = 232), physical education teachers (n = 53), food service managers (n = 33), and trained observers (n = 9).

Measures: Five process evaluation measures were created: Physical Education Questionnaire (PEQ), Intervention Questionnaire (IQ), Food Service Manager Questionnaire (FSMQ), Classroom Observation (CO), and School Nutrition Environment Observation (SNEO).

Analysis: Interrater reliability and internal consistency were assessed on all measures. Analysis of variance and χ(2) were used to compare differences across study groups on questionnaires and observations.

Results: The PEQ and one subscale from the FSMQ were eliminated because their reliability coefficients fell below acceptable standards. The subscale internal consistencies for the IQ, FSMQ, CO, and SNEO (all Cronbach α > .60) were acceptable.

Conclusions: After the initial 4 months of intervention, there was evidence that the Louisiana Health intervention was being implemented as it was designed. In summary, four process evaluation measures were found to be sufficiently reliable and valid for assessing the delivery of various aspects of a school-based obesity prevention program. These process measures could be modified to evaluate the delivery of other similar school-based interventions.

Trial registration: ClinicalTrials.gov NCT00289315.

Figure 1

Differences in mean scores on process measures. Error bars represent standard deviation. *p < .005, **p < .001. Note. Dss = Dietary environmental sub-scale; D + Iss = Dietary + Internet behavioral sub-scale; Css = Control sub-scale; Gss = General sub-scale; Rec = Recommended sub-scale; Non-rec = Non-recommended sub-scale; D = Dietary environmental; D + I = Dietary + Internet behavioral.