[Survey on the stunting of children under seven years of age in nine cities of China].

Objective: To survey the children under 7 years of age in nine cities of China for a better understanding of the current situation of childhood stunting. Methods: According to a stratified cluster sampling design, a cross-sectional survey on children under 7 years of age was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; and Guangzhou, Fuzhou and Kunming in southern China) from June to November in 2016. A total of 110 499 children were recruited. Height of children was evaluated using the growth standards for Chinese children (2009 edition) .Children with height less than the 3rd percentile of the growth standards were considered as stunting, and children with height between the 3rd and 10th percentiles of the growth standards were considered as relatively short stature. Chi-square test was used for comparison between data of boys and girls, urban and suburban, as well as among different ages and regions. Results: Totally 113 084 children under 7 years of age should be investigated and actually 110 499 children were investigated, with a rate of 97.7%. The prevalence of stunting was 1.9% (2 141/110 499) among all the children. The prevalence of stunting in urban children (1.6%, 904/55 524) was lower than that in suburban children (2.3%, 1 237/54 975, χ(2)=56.246, P<0.01). The gender difference in stunting prevalence was not statistically significant (1.9% (1 121/57 921) in boys and 1.9% (1 020/52 578) in girls, χ(2)=0.003, P=0.965). The prevalence of stunting decreased with age for children younger than 3 years, from 1.8% (312/17 080) in 0-<1 year of age group to 1.2% (168/13 740) in 2-<3 years of age group, but increased to 2.2% (240/11 073) at 6-<7 years group. Comparison among different regions showed that the stunting prevalence in southern region was higher than those in the central and northern regions (0.9% (193/20 374) in northern urban, 0.8% (154/18 486) in central urban, and 3.3% (557/16 664) in southern urban children), showing a statistical significance (χ(2)=437.736, P<0.01); 1.1% (241/21 924) in northern suburban, 1.4% (227/16 775) in central suburban and 4.7% (769/16 276) in southern suburban children, showing a statistical significance (χ(2)=646.533, P<0.01). In urban areas, the difference between the central and northern regions showed no statistical significance (χ(2)=1.429, P=0.232) and the stunting prevalence of central Chinese children was slightly higher than that of northern Chinese children in suburban areas (χ(2)=5.130, P=0.024). Among the nine cities, the stunting prevalence of Guangzhou (6.1%, 613/10 019) was higher than those of other cities (χ(2)=1 559.64, P<0.01). Among the stunting children, 78.4% (1 679/2 141) were classified as borderline or mild and only 7.2% (154/2 141) were classified as severe. The prevalence of relatively short stature was 5.2% (5 721/110 499). Conclusions: The prevalence of stunting among children under 7 years of age in nine cities of China is low and most of the stunting children were classified as mild; the prevalence of stunting in suburban children is higher than that in urban children; the gender difference show no statistical significance; and the prevalence of stunting in southern Chinese children is higher than those in central and northern Chinese children.目的： 调查分析中国9个城市（简称九市）7岁以下儿童生长迟缓的发生情况。 方法： 采用分层整群抽样方法，于2016年6—11月在北京、哈尔滨、西安（北片），上海、南京、武汉（中片），广州、福州、昆明（南片）九市对7岁以下的110 499名儿童体格生长情况进行横断面调查。以2009年中国儿童生长标准为参照，身高低于同性别同年龄身高标准第3百分位判定为生长迟缓，位于第3~10百分位判定为身高偏矮。检出率按性别、地区、年龄等分组，组间生长迟缓检出率比较采用χ(2)检验。 结果： 九市7岁以下儿童应调查113 084名，实际调查110 499名，调查率97.7%。生长迟缓总检出率为1.9%（2 141/110 499）；城区低于郊区[1.6%（904/55 524）比2.3%（1 237/54 975），χ(2)=56.246，P<0.01]；男、女差异无统计学意义[1.9%（1 121/57 921）比1.9%（1 020/52 578），χ(2)=0.003，P=0.965]；生长迟缓检出率在0~<3岁随年龄略下降[从0~<1岁组1.8%（312/17 080）至2~<3岁组1.2%（168/13 740）]，之后略提高，6~<7岁为2.2%（240/11 073）。不同地区比较，南片高于北、中片[城区3.3%(557/16 664）比0.9%(193/20 374)、0.8%(154/18 486)，郊区4.7%(769/16 276）比1.1%(241/21 924)、1.4%(227/16 775)，χ(2)=437.736、646.533，P均<0.01]；而城区北、中片差异无统计学意义（χ(2)=1.429，P=0.232），郊区中片略高于北片（χ(2)=5.130，P=0.024）。九市中广州市生长迟缓率最高（6.1%,613/10 019），各城市比较差异有统计学意义（χ(2)=1559.64，P<0.01）。生长迟缓程度构成显示以临界和轻度为主（78.4%,1 679/2 141），重度较少（7.2%,154/2 141）。身高偏矮儿童检出率为5.2%（5 721/110 499）。 结论： 九市7岁以下儿童生长迟缓处于较低流行状态，且检出生长迟缓儿童多为轻度。生长迟缓检出率郊区高于城区，男女差别不明显，南片地区高于北、中片地区。.