Process evaluation results of a cluster randomised controlled childhood obesity prevention trial: the WAVES study

Abstract

BackgroundIncreasing prevalence of childhood obesity and its related consequences emphasises the importance of developing and evaluating interventions aimed at prevention. The importance of process evaluation in health intervention research is increasingly recognised, assessing implementation and participant response, and how these may relate to intervention success or failure. A comprehensive process evaluation was designed and undertaken for the West Midlands ActiVe lifestyle and healthy Eating in School children (WAVES) study that tested the effectiveness of an obesity prevention programme for children aged 6-7 years, delivered in 24 UK schools. The four intervention components were: additional daily school-time physical activity (PA); cooking workshops for children and parents; Villa Vitality (VV), a 6-week healthy lifestyle promotion programme run by a local football club; and signposting to local PA opportunities.MethodsData relating to six dimensions (Fidelity, Reach, Recruitment, Quality, Participant Responsiveness, Context) were collected via questionnaires, logbooks, direct observations, focus groups and interviews. Multiple data collection methods allowed for data triangulation and validation of methods, comparing research observations with teacher records. The 6-stage WAVES study model ((i) Data collection, (ii) Collation, (iii) Tabulation, (iv) Score allocation and discussion, (v) Consultation, (vi) Final score allocation) was developed to guide the collection, assimilation and analysis of process evaluation data. Two researchers independently allocated school scores on a 5-point Likert scale for each process evaluation dimension. Researchers then discussed school score allocations and reached a consensus. Schools were ranked by total score, and grouped to reflect low, medium or high intervention implementation.ResultsThe intervention was predominantly well-implemented and well-received by teachers, parents and children. The PA component was identified as the most challenging, VV the least. Median implementation score across schools was 56/75 (IQR, 51.0 - 60.8). Agreement between teacher logbooks and researcher observations was generally high, the main discrepancies occurred in session duration reporting where in some cases teachers’ estimations tended to be higher than researchers’.ConclusionsThe WAVES study model provides a rigorous and replicable approach to undertaking and analysing a multi-component process evaluation. Challenges to implementing school-based obesity prevention interventions have been identified which can be used to inform future trials.Trial registration ISRCTN97000586. 19 May 2010.Electronic supplementary materialThe online version of this article (10.1186/s12889-017-4690-0) contains supplementary material, which is available to authorized users.

Effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6 and 7 year olds: cluster randomised controlled trial (WAVES study)

“…Process evaluation —detailed results from the process evaluation are reported separately. 17 18 19 Briefly, the intervention was generally well implemented, although no school delivered all components completely as intended. The scores developed to represent overall fidelity of programme implementation show that just under half the schools (12/26) achieved at least 75% of the maximum possible score and only five schools failed to achieve at least 65% of that maximum.…”

“…Comprehensive process evaluation (described in more detail elsewhere 16 ) helped to contextualise the findings and to interpret the results. 17 …”

“…A detailed report on the method used to synthesise the process evaluation data is published elsewhere. 17 …”

Measuring implementation fidelity of school-based obesity prevention programmes: a systematic review

“…Operationalisation fidelity component N = 15 [ 28 , 29 , 35 – 38 , 46 – 49 , 51 , 56 , 59 – 61 , 69 , 71 , 72 , 77 , 87 ] 4. Data collection methods N = 8 [ 29 , 47 – 49 , 60 , 68 , 70 , 86 , 90 ] 5. Quantitative fidelity measures N = 13 [ 25 , 28 , 36 – 38 , 46 – 49 , 51 , 56 , 60 , 68 , 71 , 72 , 77 , 81 , 87 ] 6.…”

“…Frequency of data collection N = 22 [ 24 , 28 , 29 , 32 , 35 – 38 , 44 , 46 , 48 , 51 , 56 , 60 , 61 , 68 – 72 , 77 , 81 , 85 – 87 , 90 ] 7. Relation fidelity component and programme outcome assessed N = 5 [ 25 , 28 , 29 , 46 , 56 , 81 ] Methodological qualitsy per fidelity component • Low (< 50%) N = 11 [ 24 , 25 , 30 , 32 , 35 , 44 , 59 , 69 , 70 , 85 , 90 ] • Moderate (50–75%) N = 11 [ 29 , 36 – 38 , 47 , 49 , 51 , 61 , 68 , 71 , 72 , 77 , 81 , 86 , ...…”