Trends in the burden of diseases and their associations with multidimensional development among children and adolescents in China from 2000 to 2019: a retrospective analysis of a nationwide, repeated, cross-sectional survey

Background Rapid social progress has transformed the health profile of Chinese children and adolescents, with declining diseases associated with poverty and rising diseases associated with wealth. This study aims to describe national trends in disease transitions and examine their associations with multidimensional provincial development. Methods In this retrospective study, we analysed data from the 2000, 2005, 2010, 2014, and 2019 waves of the nationwide, repeated, cross-sectional Chinese National Surveys on Students' Constitution and Health in Han Chinese children and adolescents aged 7–18 years from 30 provinces in mainland China. The survey used a multistage, stratified, cluster-sampling design with balanced distributions by age, sex, and residence (urban vs rural). Collected data were prevalences of diseases associated with wealth and development (overweight and obesity, dental caries, and visual impairment) and their coexistence (multimorbidity associated with wealth) in addition to diseases associated with poverty (undernutrition, anaemia, and Ascaris infestation), and their coexistence (multimorbidity associated with poverty). We integrated 13 provincial indicators reflecting economic, social, environmental, infrastructure, and innovation development to construct a Multidimensional Equality Development Index (MEDI) using an entropy method. To examine national trends in disease transitions and their associations with multidimensional development we used mixed-effects logistic regression and restricted cubic splines. Population-attributable fractions were estimated to describe how development domains related to disease patterns. Findings The study included 1 085 072 participants across five survey waves. Between 2000 and 2019, nationally, the prevalence of diseases associated with wealth increased and that of diseases associated with poverty declined substantially. In 2019, prevalence of visual impairment was highest (67·8%), followed by overweight and obesity (24·3%), dental caries (21·9%), multimorbidity associated with wealth (20·1%), anaemia (10·1%), undernutrition (4·7%), Ascaris infestation (0·8%), and multimorbidity associated with poverty (0·5%). The overall median MEDI score increased from 0·11 (IQR 0·09–0·16) in 2000 to 0·20 (0·15–0·28) in 2019. When data were pooled over 20 years, restricted cubic-spline analyses showed a non-linear association between MEDI score and odds of the disease outcome; higher MEDI scores were generally associated with lower odds of diseases associated with poverty, and higher odds of diseases associated with wealth (excluding visual impairment). Interpretation Multidimensional development was associated with simultaneous reductions in prevalence of diseases associated with poverty and increases in prevalence of diseases associated with wealth. Disparities in most diseases associated with wealth between higher and lower MEDI areas have largely narrowed, suggesting a potential dual burden in lower MEDI areas and the need for targeted strategies. These findings highlight the need to enhance cross-sector investments to promote balanced, sustainable improvements in child and adolescent health.