The present study demonstrates the effectiveness of a CSH intervention in fostering healthy behaviors in terms of improvements in healthy eating and active living. Over a two-year period, APPLE Schools changed their school environments and attending students reported increases in the consumption of fruits and vegetables along with decreases in energy intake, were more physically active, and exhibited less obesity compared to students elsewhere in the province.
Public health research is increasingly aiming to identify "best practice" and "practice based evidence" rather than to demonstrate universal evidence because the success of public health programs is greatly affected by contextual factors . The AVHPS project, a successful grassroots project, is recognized as a "best practice" of CSH in Canada . However, to our knowledge, no earlier studies have addressed the transferability of "best practice", or in other words, the extent to which the measured effectiveness of an applicable intervention could be achieved in another setting. To our knowledge, the present study is the first one where practice-based evidence of a CSH intervention was applied in a different setting while under rigorous evaluation. The demonstrated success of APPLE Schools in improving health behaviours and weight status indicates that the AVHPS model is replicable and transferable to other settings outside of the original schools in Nova Scotia, where it was developed as a grassroots initiative.
In light of the current obesity epidemic, there is a paucity of studies on the effectiveness of CSH programs . Although few studies have thoroughly examined CSH interventions, our results are consistent with others that have reported on the benefits of CSH in terms of increased consumption of fruits and vegetables [45, 46]. Similarly, our results are consistent with previous findings from the original AVHPS project on which the APPLE School program is based .
While we observed significant differences in diet and physical activity levels over a two-year period among students attending APPLE Schools, changes in obesity prevalence were only borderline significant. Longer follow-up and a larger number of schools are needed to establish improvements in longer term health outcomes such as body weights. Based on the encouraging results reported here, APPLE Schools is now expanding to include an additional 30 schools from Aboriginal and rural and remote communities throughout Alberta. This expansion will consider that schools vary in structure, organization, and objectives, and herewith that a standard implementation strategy for CSH is not plausible . School Health Facilitators will be placed in new APPLE Schools as they were in the original 10 APPLE School to customize the CSH approach to suite the school's needs. By tailoring the CSH approaches to each of the APPLE Schools, the intervention builds upon ongoing health promoting activities and policies. Ongoing evaluation will further establish the benefits of CSH and the APPLE Schools approach.
The 10 APPLE Schools were selected by school jurisdictions and were mostly located in socioeconomically disadvantaged neighborhoods. That these schools were "in need" of health promotion was reflected in the poor diets and low levels of physical activity among students attending these schools at baseline in 2008. However, two years into the intervention, students attending APPLE Schools had improved their eating behaviours and physical activity levels such that they approximated or exceeded the provincial average. Given the substantial morbidity and diminished quality of life associated with poor diet, physical inactivity and childhood obesity, studies are needed to demonstrate the cost-effectiveness of CSH prevention programs considering that obese children have higher healthcare cost than normal weight children . Such economic analyses will better guide public health decision makers in directing resources towards broader implementation of school-based interventions and may be instrumental in informing various policies across North America.
Strengths of the current study include its large representative sample, high response rate for school-based research, pre-intervention measurements, and the use of measured height and weight to assess body weight status. However, as with most population-based observational studies, the present study is subject to limitations. First of all, the 10 APPLE Schools were selected by school jurisdictions rather than randomly, which limits the generalizability of the results. Responses to questionnaires remain subjective and are prone to reporting error. Although individuals have a tendency to over-report levels of physical activity, it has been shown that self-reported measures of physical activity are correlated with objective measures among children . Similarly, we acknowledge the imprecision associated with the assessment of dietary energy intake through the FFQ and therefore have standardized the number of servings of fruit and vegetable consumption based on energy intake. Despite the use of a validated FFQ for this age group, limitations of self-report apply to the assessment of dietary intake in which studies have shown that individuals are more likely to underreport energy intake . Moreover, CSH aims to improve various aspects of the school environment such that they support improved dietary patterns and physical activity among students. The implementation was tailored and developed distinctively in each of the 10 APPLE Schools. Although randomized control trials provide the highest level of evidence for the evaluation of interventions, they may not be optimal for the evaluation of interventions that are tailored and develop distinctively. Furthermore, we opted for evaluation of prevalence rates that speak better to the needs of public health decision makers rather than incidence rates by following selected students over time.