Study Of Risk Prediction Model On Overweight Or Obesity Of Students

1.ObjectivesA case-control study were conducted in the Hangzhou,Wuhan and Xi'an,the objective of this study was to explore influence factors about behavioral phase,psychological factor and social support on overweight/obesity of middle school students;establish and compare behavioral?Psychological and social model on overweight/obesity of middle school students.The study in order to provide utility tools easy to operate for evaluation and prediction on overweight/obesity risk of middle school students.2.Methods?Investigation method:According to territory of our country,three cities from the east.middle and west were selected which is Hangzhou,Wuhan and Xi'an.We extracted part of first-and second-grade classes from twelve middle schools as survey source object by multistage sampling method.Case group included part overweight/obesity students from first-and second-grade classes combined with the sample size requirements and excluded not simple obesity students.Control group included normal BMI students also from first-and second-grade classes.Case students and control students 2-1 matched by same region,grade and sex.The questionnaire scale of this study was the adolescent low fat food intake behavior/vegetables intake behavior/exercise/reduce sedentary Behavior of psychological and social measurement scales,which including general demographic characteristics,behavioral phase,psychological factor?change strategy,pros,cons and self-efficacy?and social support?family support and friend support?.?Statistical method:Using SPSS20.0 version to analyze data.T test and Chi-square test were used to compare interclass equilibration first,T test was used to analyze continuous data which fit normal distribution,Chi-square test was used to analyze categorical data.Then Single factor logistic regression was used to filter influence factors by enter method.Multivariate logistic regression was used to establish regression equation.Last,Risk prediction model on overweight/obesity of stuents was built after corrected constant and transformed by formula.Hosmer-Lemeshow goodness of fit test,Area under the ROC curve and Yueden's index were used to evaluate models.Z test operated by Medcale softwares to compare AUC.Retrospective test was used to verify validation of model,accuracy and Kappa coefficient was adopted to define validation results of the model.With P<0.05 for the difference significance.3.Results?For this study,We have got 1281 subjects.case group included 427 students and control group included 854 students.486 students from Hangzhou,426 students from Wuhan,369 students from Xi'an.921 boys and 360 girls.654 junior high school students and 627 senior high school students.Equilibrium basis on demographic characteristics between case group and control group.?In the aspect of behavior,protective factors on overweight/obesity of all students were low fat food intake behavior stage,vegetable and fruit intake behavior stage,exercise behavior stage and reduce sedentary behavior stage.In the aspect of psychology,protective factors on overweight/obesity of students were vegetable and fruit intake change strategy,exercise change strategy,vegetable and fruit intake pros,exercise self-efficacy and reduce sedentary self-efficacy;Risk factor on overweight/obesity of students was low fat food intake cons.protective factors on overweight/obesity of boys were vegetable and fruit intake change strategy,exercise change strategy,vegetable and fruit intake pros,exercise self-efficacy and reduce sedentary self-efficacy.Protective factors on overweight/obesity of girls were exercise change strategy,reduce sedentary change strategy,vegetable and fruit intake pros,and reduce sedentary self-efficacy;Risk factor on overweight/obesity of girls were low fat food intake cons and reduce sedentary cons.In the aspect of social support,protective factors on overweight/obesity of students were low fat food intake family support,vegetable and fruit intake family support,reduce sedentary family support and exercise friend support.Protective factors on overweight/obesity of boys were low fat food intake family support,vegetable and fruit intake family support and exercise friend support.Protective factors on overweight/obesity of girls were low fat food intake family support,reduce sedentary family support and vegetable and fruit intake friend support.?With P<0.05 for the difference significance.?? Behavior stage for risk prediction model on overweight/obesity of students:Behavior stage for risk prediction model on overweight/obesity of boys:Behavior stage for risk prediction model on overweight/obesity of girls:Psychology for risk prediction model on overweight/obesity of students:Psychology for risk prediction model on overweight/obesity of boys:Psychology for risk prediction model on overweight/obesity of girls:Social support for risk prediction model on overweight/obesity of students:Social support for risk prediction model on overweight/obesity of boys:Social support for risk prediction model on overweight/obesity of girls:?After Hosmer-Lemeshow fitness test,model P₁^*?P2^*?P₃^*?P₆^*?P₇^*?P₈^*?P₉^*had great calibration ability?P>0.05?,calibration ability of modelP₄^*?P₅^*?not ideal.?P<0.05?.According to ROC curve by prediction probability,AUC of models bewteen 0.648 to 0.855,so separating capacity of models all great?P<0.05?.AUC of models were compared in pairs,predictive ability of P₁^*and P₄^*better than P₇^*.Predictive ability of P₂^*and P₅^*better than P₈^*.Predictive ability of P₃^*better than P9^*.Retrospective test showed that accuracy of model were good,and model had great consistency except bad kappa coefficient of P₇^*and P₈^*.4.ConclusionBehavior stage?psychological factors and social support all influence overweight/obesity of students.Overweight/obesity risk prediction model of middle school students based on behavior phase have higher predictive value.Overweight/obesity risk prediction model of girl based on psychological factors and social support have higher predictive value.Risk prediction model on overweight/obesity have better effect among girls.It prompts a neccessity that more concern on health management of diet behaviors,adopt psychological education based on transtheoretical model for girls,actively develop healthy education in the form of group.Last is that encourage students evaluate healthy risk by themselves through models and advocate self-health management concept.