Effects of a school-based intervention to reduce cardiovascular disease risk factors among secondary school students: a cluster randomized controlled trial

Abstract Background Globally, cardiovascular disease (CVD) was responsible for 17.5 million deaths, accounting for 46.2% non-communicable disease deaths. In Ghana CVDs has been the leading cause of adult death since 2001. Prevalence of CVD risk factors among adolescents in Ghana has been increasing. Objective of this study was to develop, implement and evaluate the effectiveness of a health education intervention program to reduce CVD risk factors among students. Methods A cluster randomized controlled trial was conducted with a school as cluster over a period of six-months with pre and post intervention evaluations. Participants were public secondary school students (14-19 years) from four schools in Brong Ahafo, Ghana. Students in the intervention group were trained by the researchers whereas those of the control group received no intervention. The intervention included health education and physical activity modules. Follow-up data using same questionnaire were collected within two weeks after the intervention was completed. Intention-to-treat analysis was performed after replacing missing values using multiple imputation method. The generalized linear mixed model (GLMM) was used to assess the effects of the intervention. Results Of the 848 study participants, 836 completed the final assessment at six-month. The GLMM showed the intervention was significant in attaining 0.77(p<0.001), 0.72(p<0.001), 0.47(p<0.001), 0.56(p<0.001), and 0.39(p=0.045) higher physical activity, fruits, vegetables, seafood, and water scores respectively for the intervention group over the control group. The intervention was also significant in reducing -0.15(p<0.001), -0.23(p<0.001), -0.50(p<0.001), -0.32(p<0.001), -0.90(p<0.001),-0.87(p<0.001),-0.38(p<0.001),-0.63(p<0.001),-1.63(p<0.001),-0.61(p<0.001),and -1.53(p=0.005) carbohydrates, fats and oils, fried eggs, fried chicken, carbonated drinks, sugar, sweet snacks, salted fish, weight, BMI, and diastolic BP. The ‘’odds’’ of quitting alcohol use in the intervention group was 1.06 times more than in control group. There was no significant effect of the intervention on reducing systolic BP. Conclusions The intervention had positive effect on increasing physical activity, promoting healthy diet, reducing alcohol consumption, weight, BMI, and diastolic BP among students in the intervention arm of the study but had no effect on systolic BP. Findings from this study is recommended to be adopted in the educational curricula in secondary schools. Keywords: Cardiovascular disease, risk factors, behavioral modification intervention, secondary school students, adolescents