Cohort Study On Influencing Factors Of Preschool-children Physical Fitness Based On Decision Tree

ObjectiveAnalyze the level and changes of physical fitness in preschooler through tracking measurement,and investigate and analyze the influencing factors of physical fitness changes in preschooler.On this basis,build a decision tree model of physical fitness,explore the key factors that affect preschooler’s physical fitness and explore their interactions,aiming to improve the research system for the promotion of the physical fitness of preschooler.MethodThrough the cluster stratified random sampling method,a total of 1,276 children aged 3 to 6 years old were recruited from 23 kindergartens in Nanchang,and the parents had agreed and signed an informed consent form.A cohort study design was used to measure the height,weight,10 m shuttle run,The standing long-jump tests,tennis long throw,and double-foot continuous jump,sitting position forward bending,walking balance beam,8 individual qualitative scoring items of the tested children at baseline and one year later.according to the Handbook of National Physical Fitness Measurement Standards(Preschool Children Part),physical fitness scores are performed according to age groups,each with a full score of 5 points,totaling 40 points,and then the difference between the two stages of physical fitness scores is calculated.According to the needs of the decision tree model of this study,the target variable(physical fitness difference)is classified into two categories,which are divided into “improvement(including constant)”(difference ≥0 points)and “reduction”(difference <0)2 Levels.The questionnaire investigates the factors affecting the physical fitness of the tested children,including 6 first-level indicators,including birth information,parenting methods,meditation and physical activity,diet and nutrition,sleep,and parental conditions,and 59 second-level indicators.Integrate measurement data and questionnaire results,and use IBM SPSS modeler software to create a CHAID decision tree model.Result1.After one year,eight physical fitness index levels of children(height,weight,10 m shuttle run,standing long-jump tests,tennis long throw,double-foot continuous jump,sitting position forward bending,walking on balance beam)were significantly improved;The scores of sitting position forward bending,tennis long throw,standing long-jump anddouble-foot continuous jump were significantly improved after one year,but the scores of walking on balance beam were significantly decreased after one year.2.The CHAID decision tree model constructed by this research is 5 layers high,with 33 leaf nodes,and the model accuracy rate is 84.17%.3.Sort the variable importance according to the position of the node where the variable is located.The 7 variables have a strong correlation with the target variable.The order of importance of each variable is the weekend physical activity(PA),the weekend moderate to vigorous physical activity(MVPA),mother’s body mass index(BMI),mother’s participation in sports frequency,father’s education,mother’s education,school day PA.Among them,3 factors(weekend PA,weekend MVPA,school day PA)are related to PA;4 factors(mother’s BMI,mother’s participation in sports frequency,father’s education,mother’s education)are related to parents’ situation.4.The decision tree model shows that the physical fitness improvement of preschool children with the root node variable PA “>1.5h/d” on weekends is significantly higher than that of children with PA “30min～≤1.5h/d” and “≤30min/d”(P<0.01)on weekends;In the second layer of leaf nodes,the three split nodes are all weekend MVPA.Combining with the first layer nodes,it is found that among the children with weekend PA “>1.5h/d”,the children with weekend MVPA “>1h/d” and“30min～ ≤ 1h/d” have significantly improved physical fitness than those with“≤30min/d” preschooler(P < 0.01);among them,preschooler with MVPA“≤30min/d” on weekends are classified according to the frequency of their mothers’ participation in sports.preschooler whose mothers participate in sports 6 times a week or more have improved their physical fitness significantly higher than those with 0 times a week Toddlers(P=0.001);the children with MVPA “30min～≤1h/d”on weekends were divided according to the mother’s BMI.The children with the mother’s BMI “≥24.17” had a significantly lower physical fitness than those with the mother’s BMI “<24.17”(P<0.001),the physical fitness improvement of preschooler with mother’s BMI “<24.17” was significantly higher than that of preschooler with mother’s BMI “≥24.17”(P<0.001);preschooler with MVPA “>1h/d” on weekends were classified according to their father’s education.When the educational background is “≤2”(vocational high school/secondary school/technical school high school or below),the physical fitness improvement of children is significantly higher than that of children with “>2”(P=0.008);the descendants of the father’s educational background are respectively belts The child goes out for a few days with the school day PA.The PA repeatedly appeared in the third and fourth levels on school days.Among the children with weekend PA “30min～≤1.5h/d”,the children with weekend MVPA “>1h/d” and “30min～≤1h/d” improved their physical fitness significantly than those with “≤30min/d”(P<0.001).The downward branch of“≤30min/d” is the school day MVPA.In addition to 7 important variables,breakfast on school day,burgers,puffed food,father’s BMI,and taking children out for a few days,School day MVPA,father’s love for sports,father’s occupation,weekend breakfast,etc.are all statistically significant leaf node variables.Conclusion1.The flexibility,explosive force and coordination ability of trunk and lower limbs,as well as the muscle strength of upper limbs and waist and abdomen were significantly improved after one year;But the balance ability decreased significantly after one year.2.The model of decision tree established in this study has high accuracy and many leaf nodes,which can meet the needs of the research on the influencing factors of children’s physical health.3.According to the importance,the key factors influencing the physical health of children were weekend physical activity time,mother BMI,mother participation frequency,school day activity time,father education and mother education.Among them,the physical activity and the mother’s condition factors are the most important factors that affect the physical health of children.4.In order to improve the physical health level of children,the physical activity time of children at weekends is more than 1.5h/d.At the same time,30minutes/day weekend physical activity time can be used as the threshold of physical decline of children.The physical health of children is affected by the degree of obesity and the frequency of activity of mothers.Physical activities,education of father and mother,and diet style are of great significance to the prevention of different types of children’s physical fitness.