In countries undergoing rapid economic transition such as China, rates of increase in childhood obesity exceed that in the West. However, prevention trials in these countries are inadequate in both quantity and methodological quality. In high-income countries, recent reviews have demonstrated that school-based prevention interventions are moderately effective but have some methodological limitations. To address these issues, this study evaluated clinical- and cost- effectiveness of the Chinese Primary School Children Physical Activity and Dietary Behaviour Changes Intervention (CHIRPY DRAGON) developed using the United Kingdom Medical Research Council complex intervention framework to prevent obesity in Chinese primary-school–aged children. In this cluster-randomised controlled trial, we recruited 40 state-funded primary schools from urban districts of Guangzhou, China. A total of 1,641 year-one children with parent/guardian consent took part in baseline assessments prior to stratified randomisation of schools (intervention arm, 20 schools, n = 832, mean age = 6.15 years, 55.6% boys; control arm n = 809, mean age = 6.14 years, 53.3% boys). The 12-month intervention programme included 4 school- and family-based components delivered by 5 dedicated project staff. We promoted physical activity and healthy eating behaviours through educational and practical workshops, family activities, and supporting the school to improve physical activity and food provision. The primary outcome, assessed blind to allocation, was between-arm difference in body mass index (BMI) z score at completion of the intervention. A range of prespecified, secondary anthropometric, behavioural, and psychosocial outcomes were also measured. We estimated cost effectiveness based on quality-adjusted life years (QALYs), taking a public sector perspective. Attrition was low with 55 children lost to follow up (3.4%) and no school dropout. Implementation adherence was high. Using intention to treat analysis, the mean difference (MD) in BMI z scores (intervention − control) was −0.13 (−0.26 to 0.00, p = 0.048), with the effect being greater in girls (MD = −0.18, −0.32 to −0.05, p = 0.007, p for interaction = 0.015) and in children with overweight or obesity at baseline (MD = −0.49, −0.73 to −0.25, p < 0.001, p for interaction < 0.001). Significant beneficial intervention effects were also observed on consumption of fruit and vegetables, sugar-sweetened beverages and unhealthy snacks, screen-based sedentary behaviour, and physical activity in the intervention group. Cost effectiveness was estimated at £1,760 per QALY, with the probability of the intervention being cost effective compared with usual care being at least 95% at a willingness to pay threshold of £20,000 to 30,000 per QALY. There was no evidence of adverse effects or harms. The main limitations of this study were the use of dietary assessment tools not yet validated for Chinese children and the use of the UK value set to estimate QALYS. This school- and family-based obesity prevention programme was effective and highly cost effective in reducing BMI z scores in primary-school–aged children in China. Future research should identify strategies to enhance beneficial effects among boys and investigate the transferability of the intervention to other provinces in China and countries that share the same language and cultures. ISRCTN Identifier ISRCTN11867516.

Analyses of the effects of pit and fissure sealant have been based on small samples and lack large-scale field evaluation data in China. The aim of this study was to understand the effect of pit and fissure sealant in preventing caries in the first permanent molars (FPMs) of children in Guangzhou. We conducted a population-based cohort study using the database of the pit and fissure sealant program of Guangzhou. The carious status and sealant retention of the FPMs were assessed in 4,822 school children who received pit and fissure sealant 3 years prior to the study. The control group included 4,396 children who had indications for receiving pit and fissure sealant but were not treated and were matched according to sex, age and school. In the sealant group, the rate of sealant retention in the FPMs was 72.2%. Children in the sealant group had a 37% decreased risk of dental caries compared with the control group (adjusted HR = 0.63 [95% confidence interval (CI), 0.57–0.69], P < 0.001). Compared to no sealant use, the use of pit and fissure sealants reduced the risk of developing dental caries by 44% after 3 years in the FPMs of children from rural areas, reflecting a greater reduction than that among urban children (35%) during the same period (urban: adjusted hazard ratio (HR) = 0.65 [95% CI, 0.58–0.72]; rural: adjusted HR = 0.56 [95% CI, 0.45–0.70], P < 0.001). The mean number of decayed, missing, or filled permanent teeth (DMFT) in the control group was higher than that in the sealant group, and the difference was statistically significant regardless of sex. Pit and fissure sealant has a significant preventive effect against dental caries in the FPMs, especially for children in rural areas; thus, this sealant represents an effective technique for preventing and controlling dental caries.

Objectives: Rapid socioeconomic and nutrition transitions in Chinese populations have contributed to the growth in childhood obesity. This study presents a cost-effectiveness analysis of a school- and family-based childhood obesity prevention programme in China.Methods: A trial-based economic evaluation assessed cost-effectiveness at 12 months. Forty schools with 1,641 children were randomised to either receive the multi-component (diet and physical activity) intervention or to continue with usual activities. Both public sector and societal perspectives were adopted. Costs and benefits in the form of quality-adjusted life years (QALYs) were compared and uncertainty was assessed using established UK and US thresholds.Results: The intervention cost was 35.53 Yuan (£7.04/US$10.01) per child from a public sector perspective and 536.95 Yuan (£106/US$151) from a societal perspective. The incremental cost-effectiveness ratio (ICER) was 272.7 Yuan (£54/US$77)/BMI z-score change. The ICER was 8,888 Yuan (£1,760/US$2,502) and 73,831 Yuan (£14,620/US$20,796) per QALY from a public sector and societal perspective, respectively and was cost-effective using UK (£20,000) and US (US$50,000) per QALY thresholds.Conclusion: A multi-component school-based prevention programme is a cost-effective means of preventing childhood obesity in China.

In developing countries, obesity traditionally affectsmore affluent children, butis spreading to a wider social group. Understanding the perceivedcontributors can provide valuable insights to plan preventive interventions. We exploreddifferences in the perceived causes of childhood obesity between local and migrant communities in a major Chinese city. We conducted 20 focus groups (137 parents, grandparents, school teachers) and 11semi-structured interviews with school Principals from migrant and local communities in Guangzhou. Data were transcribed and analysed using a thematic approach. We found that Lack of influence from grandparents, who were perceived to promote obesogenic behaviorin local children, fewer opportunities for unhealthy snacking and less pressure for academic attainment leading to moreactive play were interpreted as potential “protective” factors among migrant children. Nevertheless, two perceived causes of obesity were more pronounced in migrant than local children: lack of parental monitoring after-school andunsafe neighborhoods limiting physical-activity. Two barriers that restricted child physical activity were only found in the migrant community: limited home space, and cultural differences, inhabitinginteractive play with local children. Future interventions should consider uniquedeterminants of obesity in children from different social backgrounds, with tailored strategies to prevent further rise of the epidemic.