Effects of a school-based health intervention and cross-sectional associations of schoolchildren’s academic performance, selective attention and health-related quality of life in Port Elizabeth, South Africa

Background Globally, only one in five children achieve the recommended 60 minutes of moderate-to-vigorous intensity physical activity per day. This number is even lower in low- and middle-income countries such as South Africa, where only half of all children and adolescents achieve the global physical activity recommendation. Regular physical activity is associated with children’s mental health and wellbeing, academic performance and the ability to pay attention at school. However, many South African primary schools located in disadvantaged areas, do not offer regular Physical Education classes due to a lack of facilities and equipment, insufficiently trained teachers and the school subject’s low status. Furthermore, access to adequate sanitation facilities and clean water are often lacking in disadvantaged primary schools. This in turn increases the risk of soil-transmitted helminths infections. Being infected with parasitic worms such as Ascaris lumbricoides and Trichuris trichiura, may lead to symptoms such as abdominal pain, (bloody) diarrhoea and anaemia. Moreover, soil-transmitted helminth infections may lead to growth retardation, school absenteeism, impaired cognitive abilities and reduced physical fitness. Therefore, children from low resourced communities are at an increased risk of ill health which may hamper their development, wellbeing, and academic success. Aim This PhD project aims to investigate health indicators and the effect of a 20-week multicomponent school-based physical activity intervention. Our study sample included approximately 1000 fourth grade schoolchildren from disadvantaged primary schools in Port Elizabeth, South Africa. The specific objectives were i) to explore cross-sectional associations and possible determinants of selective attention and academic performance; ii) to investigate the associations between health-related quality of life, self-reported physical activity and cardiorespiratory fitness; iii) to evaluate the effect of a 20-week school-based physical activity intervention program on academic performance, selective attention and health-related quality of life. Methods The disease activity and schoolchildren’s health study is a cluster-randomized controlled trial with a twice 10 week multicomponent intervention program. Eight quintile three schools were selected based on their classification (quintile 1 represents the poorest schools, while quintile 5 reflects the least poor schools), geographic location, population demographics and the number of students in the grade four classes (at least 100 children). The schools are located in and around Port Elizabeth in south-eastern South Africa. Four schools are in the areas of Kwazakhele, Motherwell, New Brighton and Zwide, which are referred to as townships (mainly inhabited by black Africans who mostly speak Xhosa). The additional four schools are in the areas of Schauderville, Helenvale, Hillcrest and Booysenspark, which are colloquially referred to as the Northern areas (mainly inhabited by coloured people whose native language is Afrikaans). Physical fitness was assessed via the 20-m shuttle run test (VO2max) and upper body strength was determined with the grip strength test. Self-reported physical activity was measured with the health-behaviour of school-aged children survey and health-related quality of life was assessed with the KIDSCREEN-27 questionnaire, representing wellbeing. Selective attention was assessed with the pencil and paper version of the d2-test of attention measuring concentration performance and error percentage. The averaged end-of-year school results (Maths, Life Skills, Home Language, and Additional Language) were used as an indicator of academic performance. Demographic data and socio-economic status were captured with a questionnaire. Stool samples were analysed with the Kato-Katz thick smear technique to diagnose soil-transmitted helminth infections. When soil-transmitted helminth infections were detected, children were treated with Albendazole (single dose, 400mg) after each assessment. Haemoglobin levels and anthropometric indicators were measured with standard tools. The multidimensional physical activity intervention was implemented in four schools, whereas four schools served as control. The intervention lasted for 2x10 weeks and consisted of five parts: i) two Physical Education lessons per week, ii) weekly moving-to-music classes, iii) daily in-class physical activity breaks and iv) physical activity homework as well as v) the creation of a low-cost physical activity-friendly school environment. Results At baseline, the study population consisted of 1009 primary schoolchildren aged 9-12 years (501 girls, 508 boys) from 26 school classes. Cross-sectional baseline data revealed that higher academic achievement and selective attention were associated with higher shuttle run performance (p<0.05; p<0.001). Furthermore, lower selective attention and lower school grades were observed in children with soil-transmitted helminth infection (p<0.05; p<0.001). Higher self-reported physical activity was associated with health-related quality of life (p<0.001). The five dimensions of health-related quality of life are: physical wellbeing, psychological wellbeing, parent relations and autonomy, social support and peers and school. We found small but significant group differences across all five dimensions of health-related quality of life when comparing children with low and high self-reported physical activity (p