[Assessment of prevalence of malnutrition among Chinese primary and secondary school students and analysis of policy effect during the period of the Program for the Development of Chinese Children 2011-2020].

OBJECTIVE: To evaluate the change of prevalence of malnutrition among Chinese primary and secondary school students and to analyze the policy effect during the period of the Program for the Development of Chinese Children 2011-2020 (PDCC 2011-2020). METHODS: The data of Chinese students aged 7 to 18 years were extracted from 8 successive cross-sectional surveys of the Chinese National Survey on Students ' Constitution and Health (CNSSCH) from 1985 to 2019. Malnutrition of students was evaluated according to the screening standard for malnutrition of school-age children and adolescents. The changes of prevalence of malnutrition among primary and secondary school students were described by gender, urban and rural areas, age group and province, from 2010 to 2019. The Joinpoint regression model was used to analyze the trajectory of the prevalence of malnutrition among students aged 7 to 18 years from 1985 to 2019, so as to evaluate the policy effect of the PDCC 2011-2020. RESULTS: The prevalence of malnutrition among primary and secondary school students in China decreased from 12.7% in 2010 to 8.5% in 2019. The prevalence of malnutrition among boys and girls, urban and rural students, and students of all age groups showed a continuous downward trend (Ptrend < 0.001) from 2010 to 2019. From 2010 to 2019, 27 of the 31 provinces (autonomous regions and municipalities) saw a significant decrease in the prevalence of malnutrition among primary and secondary school students. Joinpoint regression model showed that the prevalence of malnutrition among Chinese primary and secondary school students continued to decline from 1985 to 2019, but 2010 was the turning point in the downward trend. From 1985 to 2010, the prevalence of malnutrition among primary and secondary school students decreased by an average of 2.4% per year (95%CI: 1.9%-2.8%, P < 0.001), and the downward trend accelerated after 2010, with an average annual decline of 4.3% (95%CI: 2.4%-6.2%, P < 0.001). CONCLUSION: The prevalence of malnutrition among primary and secondary school students in China continued to decline from 2010 to 2019, achieving the goal of controlling the prevalence of malnutrition among primary and secondary school students in the PDCC 2011-2020. The PDCC 2011-2020 may have played an important role in improving the malnutrition among primary and secondary school students. However, the problem of malnutrition among primary and secondary school students still exists, and it is still necessary to adhere to the coverage and financial support of the nutrition improvement plan in areas with high incidence of malnutrition.

[Trends of the disease burden of intellectual disability among children and adolescents from 1990 to 2019 in China].

Objective: This study aims to analyze the disease burden of intellectual disability among Chinese children and adolescents aged 0-19 years in 2019 and its trends from 1990 to 2019. Methods: Data were gathered from the Global Burden of Disease study. The prevalence and years lived with disability (YLDs) of intellectual disability among Chinese children and adolescents were compared with the global average by gender, age group, and severity of disability in 2019. Joinpoint regression model was used to analyze the trends in the prevalence and YLDs of intellectual disability among Chinese children and adolescents from 1990 to 2019. Results: The prevalence and YLDs of intellectual disability among Chinese children and adolescents in 2019 were 1 522.65 per 100 000 (95%UI: 1 228.62 per 100 000-1 817.55 per 100 000) and 109.81 per 100 000 (95%UI: 72.15 per 100 000-158.09 per 100 000), respectively, which were lower than the global average. The prevalence and YLDs of severe intellectual disability in China were slightly higher than the global average. The average annual percent changes in the prevalence and YLDs of intellectual disability among Chinese children and adolescents were -0.23% (95%CI: -0.26%--0.21%, P<0.001) and 0.74% (95%CI: 0.66%-0.81%, P<0.001) from 1990 to 2019, respectively. The prevalence and YLDs of severe intellectual disability showed continuously increasing trends over the past 30 years. Conclusions: The disease burden of intellectual disability among Chinese children and adolescents was lower than the global average in 2019, but severe intellectual disability was higher than the global average. The prevalence of intellectual disability among Chinese children and adolescents showed an overall decrease, while YLDs showed an increasing trend from 1990 to 2019.

[Regional inequality of height among Chinese Han students aged 7 to 18 years from 1985 to 2014].

Objective: To analyze the regional inequality of height among Chinese Han students aged 7 to 18 years from 1985 to 2014. Methods: The Chinese Han students aged 7 to 18 years with complete basic information and height data from 30 mainland provinces (excluding Hong Kong, Macao, Taiwan and Tibet in China) were extracted as participants from 6 successive cross-sectional surveys of the Chinese National Survey on Student's Constitution and Health (CNSSCH). After excluding extreme and illogical cases, a total of 1 495 182 students were included in the analysis. The data of gross domestic product (GDP) per capita of each province at each survey year were collected from the website of National Bureau of statistics of China. Mann-Kendall trend test was used to analyze the trend of mean height across years. Weighted linear regression model was used to analyze the association between mean height of students aged 7 to18 years and GDP per capita at provincial level. Height difference, height ratio, slope index of inequality (SII) and relative index of inequality (RII) were used to measure the height inequality by gender and age groups. Results: The mean height of Chinese Han students aged 7 to 18 years increased from 144.9 cm in 1985 to 151.8 cm in 2014 (P<0.05). The height difference between urban and rural students in all age groups was reducing (P<0.05). The height difference between urban and rural boys aged 13 to 15 years decreased from 5.3 cm in 1985 to 2.5 cm in 2014, and the difference between urban and rural girls aged 7 to 12 years decreased from 4.6 cm in 1985 to 2.4 cm in 2014. The mean height of students aged 7 to 18 years was positively associated with GDP per capita in all survey years for both genders (P<0.001). Taking Shanghai and Guizhou as the representatives of economically developed and underdeveloped provinces, from 1985 to 2014, the height differences between two provinces were 6.8-9.2 cm, 8.0-12.4 cm and 6.3-8.8 cm for boys aged 7 to 12 years, 13 to 15 years and 16 to 18 years, respectively, and the height ratios were stable at 1.05-1.07, 1.05-1.08 and 1.04-1.05 respectively. From 1985 to 2014, the SII of mean height for boys in three age groups were 4.4-6.2, 4.9-6.7 and 2.5-4.7, respectively. The RII of mean height of boys in three age groups were 1.03-1.05, 1.03-1.04 and 1.01-1.03, respectively. In the same period, the SII of mean height for girls in three age groups were 4.2-6.2, 2.8-4.5 and 2.5-3.9, and the RII were 1.03-1.05, 1.02-1.03 and 1.02, respectively. Conclusion: From 1985 to 2014, the urban-rural inequality of height development among Chinese Han students aged 7 to 18 years was narrowing, but the socio-economic inequality of height persisted and remained at a relatively stable level.

[Subnational inequalities of early marriage and fertility among Chinese females from 1990 to 2010].

OBJECTIVE: To analyze the inequality of early marriage and adolescent fertility with respect to local economic development among Chinese females aged 15-19 years from 1990 to 2010. METHODS: Aggregated data were extracted from the Chinese National Census from 1990 to 2010. We calculated the ever-married rate and fertility rate of female adolescents aged 15-19 years. Using gross domestic product (GDP) per capita as an indicator for socio-economic status of a province, we calculated the slope index of inequality (SII) and the concentration index (CI) to analyze the subnational inequalities of early marriage and adolescent fertility. Weighted linear regression models were also established to assess the associations between GDP per capita and the ever-married rate/fertility rate. RESULTS: The ever-married rate for Chinese female adolescents aged 15-19 years decreased from 4.7% in 1990 to 1.2% in 2000, and rebounded to 2.1% in 2010. From 1990 to 2000, the fertility rate decreased from 22.0 per 1 000 to 6.0 per 1 000, and further decreased to 5.9 per 1 000 in 2010. In 1990, the socio-economic inequalities of the ever-married rate and fertility rate for female adolescents aged 15-19 years were not statistically significant (P for SII or CI>0.05). The values of SII revealed that, in 2000 and 2010, female adolescents with the lowest GDP per capita had an ever-married rate 2.4% (95%CI: 0.4-4.4) and 2.3% (95%CI: 0.3-4.2) higher than those with the highest GDP per capita, respectively. In the meantime, in 2000 and 2010, female adolescents with the lowest GDP per capita had a fertility rate 12.9 per 1 000 (95%CI: 5.4-20.5) and 9.3 per 1 000 (95%CI: 4.6-14.0) higher than those with the highest, respectively. In 2000 and 2010, the CIs for marriage were -0.32 (P=0.02) and -0.17 (P=0.03), respectively, and the CIs for childbirth were -0.37 (P<0.01) and -0.26 (P<0.01), respectively. In 2000, the ever-married rate and the fertility rate were estimated to increase by 1.4% (95%CI: 0.1-2.7) and 7.9 per 1 000 (95%CI: 2.9-12.8) with 100% increase in GDP per capita, respectively; in 2010, the numbers were 1.5% (95%CI: 0.1-2.9) and 6.7 per 1 000 (95%CI: 3.2-10.1), respectively. CONCLUSION: Subnational socio-economic inequality of early marriage and adolescent fertility existed in 2000 and 2010. Female adolescents residing in less-developed areas were more likely to engage in early marriage and childbirth. Reducing income inequality and increasing education investment for poverty-stricken areas seem to be effective measures to reduce this inequality.

[Secular trends and geographic disparities of all-cause mortality among Chinese adolescents aged 10-24 years, between 1953 and 2010].

Objective: To analyze the secular trends and geographic disparities of all-cause mortality among Chinese adolescents aged 10-24 years over the period of 1953-2010. Methods: Data were extracted from the Chinese National Census in 1953-2010. We calculated the all-cause mortality and annualized rates of the changes. Using the provincial gross domestic product (GDP) per capita as an indicator of regional socio-economic development level, we calculated the Wagstaff normal concentration indices for adolescent mortality. Results: Over the period of 1953-2010, the general patterns of Chinese adolescent mortality appeared higher in males than those in females, higher in the 20-24-year-old than those in the 15-19 year-old and in the 10-14 year-old groups, higher in adolescents from the western than those in the eastern regions. The mortality of adolescents decreased from 554.6/100 000 in 1953-1964 to 55.7/100 000 in 2010 in males and decreased from 488.4/100 000 to 26.7/100 000 in females, respectively. The percentage of decrease for females (94.5%) was higher than that for males (90.0%). In 1981-2010, the highest annualized rate of decline for males was seen in Beijing (4.4%), with the lowest seen in Qinghai (0.1%). For girls, Hubei showed the highest annualized rate of decline (6.4%) while Qinghai the lowest (0.8%). Provinces that with higher mortality tended to have lower annualized rate of decline. The concentration indices for boys were -0.07 (95%CI: -0.11- -0.03), -0.13 (95%CI: -0.18- -0.08), and -0.16 (95%CI: -0.22- -0.10) in 1990, 2000, and 2010, respectively, and were -0.07 (95%CI: -0.13- -0.02), -0.18 (95%CI: -0.24- -0.12), and -0.18 (95%CI: -0.26- -0.09) respectively in girls. The indices among 1990, 2000, and 2010 did not show statistically significantly differences, both for boys and girls (P>0.05). Conclusions: Over the half century, the mortality of Chinese adolescents showed dramatic decreasing trend. However, in terms of death rates, gender and geographic disparities were consistently seen in the adolescents.

[Analysis on the urban-rural disparity of childhood stunting and its association with economic growth among Chinese Han students aged 7-18 years old].

Objective: To analyze the urban-rural disparity of childhood stunting and its association with subnational economic growth among Chinese Han students aged 7-18 years. Methods: We used the data from 2014 Chinese National Survey on Students' Constitution and Health. 213 940 Chinese Han students aged 7-18 years with complete height records were included in this study. Stunting was defined according to the Screening Criteria of Malnutrition for School-age Children and Adolescents(2014 version, in Chinese). We divided students into two groups (economically developed and underdeveloped areas) according to the provincial GDP per capita. Spearman correlation coefficient was used to explore the association between the difference of urban-rural stunting prevalence and the provincial GDP per capita. Logistic regression models were established to assess the risk of stunting in rural children compared with urban children. Results: Among 213 940 students, 107 033 (50.0%) were from urban areas. The average height of 7-18 years old and 18 years old [(152.9±15.7) and (166.1±8.7) cm] of urban students were both higher than those of rural students [(150.7±16.0) and (165.1±8.6) cm] (P<0.001). The stunting prevalence of Chinese urban students (0.4%) was statistically significant lower than that of rural students (1.1%) (P<0.001), which was consistent in all age groups (P<0.05). The urban-rural disparity was found in 60% (18/30) of Chinese provinces. The difference of urban-rural stunting prevalence was negatively associated with provincial GDP per capita (r=-0.62, P<0.001). In economically underdeveloped areas, the risk of stunting for rural students aged 7-9 years was 4.69 (95%CI: 2.93-7.52) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.44 (95%CI: 2.02-2.96). In economically developed areas, the risk of stunting for rural students aged 7-9 years was 5.43 (95%CI: 3.67-8.03) times that for urban children, while for students aged 10-18 years, the odds ratio was 2.15 (95%CI: 1.85-2.49). Conclusions: The urban-rural disparity of childhood stunting existed in most places in China. The difference of growth retardation between urban and rural areas was related to regional economic development.