[Analysis of developmental coordination disorder in Chinese children]

Objective: To investigate the prevalence of children's developmental coordination disorder (DCD) and its distribution based on different family socioeconomic characteristics in China, in order to provide a theoretical basis for early prevention, diagnosis, and intervention for DCD. Methods: From June to October, 2016, 1 887 children aged 3-10 years from 20 kindergartens and 10 elementary schools from 8 cities in seven geographic areas of China using a stratified cluster sampling method were recruited. With a cross-sectional design, parents were asked to report on their basic information. Children' s motor ability was assessed using the movement assessment battery for children-second edition (MABC-2). Children were grouped by age, sex, body mass index (BMI), one-child status, and family structure. Chi-square test and one-way ANOVA were used to compare family socioeconomic characteristics of children between different groups. Results: Among the 1 887 children, there were 1 110 (58.8%) preschool children (3-6 years of age) and 777 (41.2%) school-aged children (7-10 years of age). There were 982 males (52.0%) and 905 females (48.0%). A total of 5.5% (104 cases) children were diagnosed with DCD, 10.4% (197 cases) with suspected DCD, and 84.1% (1 586 cases) as typical motor developing children. There were no significant differences in prevalence of diagnosed and suspected DCD among different regions (χ²=17.342 and 4.877, P=0.173 and 0.560), total motor coordination score (F=2.759, P<0.05), and the scores of all dimensions (manual dexterity, positioning and grabbing, balance: F=9.276, 5.277, 3.706, all P<0.01). The prevalence of DCD in preschool children was significantly higher than that in school-age children (χ²=11.891, P<0.01). Girls were significantly better than boys in total motor coordination, manual dexterity, and balance (all P<0.01). Boys were significantly better than girls in positioning and grabbing (P<0.01). The prevalence of DCD in boys was significantly higher than that in girls (70 boys (7.1%) and 34 girls (3.8%), χ²=28.508, P<0.01). The total motor coordination ability, manual dexterity and balance of children who are overweighted (BMI>18 kg/m²) were significantly lower than those of children of normal weight (BMI≤18 kg/m²) (all P<0.01). The prevalence of suspected DCD children who are overweighted was significantly higher than that of children of normal weight (χ²=4.369, P<0.05). The difference of total motor coordination ability (F=6.811, P<0.01) and the prevalence of DCD (χ²=14.902, P<0.01) among different family structures were statistically significant. The total motor coordination ability and balance ability of children from multi-child family were better than those of children from one-child family (both P<0.05). Conclusion: The motor coordination ability of Chinese children is well-developed, with differences among different regions, gender, age, BMI, and family structure.