【摘要】 目的建立中学生超重/肥胖的风险评估模型,探索其最佳切点值,为评估中学生超重/肥胖风险及对高危者进行早期干预提供参考。方法采用多阶段整群抽样方法在杭州、武汉、西安抽取12所中学的427例超重/肥胖中学生为病例组,按照同地区、同年级、同性别,以1∶2进行个体匹配,得到854例BMI正常的对照组。测量其行为、心理和社会因素情况采用《中文版青少年低脂食物摄入、果蔬摄入、体育锻炼、减少久坐的行为心理社会因素测定量表》;建立风险评估模型采用多因素Logistic回归分析;评价模型采用Hosmer-Lemeshow拟合优度检验、受试者工作特征曲线下面积(AUC)和约登指数;确定模型验证效果采用分类准确率和Kappa系数。结果行为因素评估中学生超重/肥胖风险评估模型中含低脂食物摄入、果蔬摄入、锻炼、减少久坐的行为阶段;其预测值与观测值的差异不具有统计学意义,标定能力较好(χ~2=9. 19,P=0. 327); AUC为0. 75(0. 72,0. 77),P<0. 001,最佳切点值为0. 38,敏感性为0. 61,特异性为0. 75;回代检验模型的准确率为77. 1%,Kappa值为0. 48,P<0. 001。心理因素评估中学生超重/肥胖风险评估模型标定能力较差(χ~2=19. 26,P=0. 014)。社会因素评估中学生超重/肥胖风险评估模型的预测结果与实际结果的一致性较差(Kappa=0. 30,P<0. 001)。结论行为因素评估中学生超重/肥胖风险模型具有良好的预测价值,最佳切点值为0. 38;心理、社会因素对超重/肥胖有一定影响,但可能不是直接作用。更多还原

【Abstract】 Objective To establish the risk evaluation model of overweight/obesity among middle school students,explore the optimal cut-off value,provide a reference for predicting overweight/obesity risk among middle school students and taking early intervention among the high-risk students. Methods A total of 427 middle school students with overweight/obesity were selected from 12 middle schools in Hangzhou,Wuhan,and Xi’an by multi-stage cluster sampling method,854 middle school students of the same area,grade,and gender with normal BMI were selected as control group. Adolescents’ behavioral,psychological,and social factor scale about low-fat food intake,fruit intake,and vegetable intake( Chinese version) was used to measure behavioral,psychological,and social factors of these students,then the results were analyzed by multivariate logistic regression analysis based on risk assessment model. The model was evaluated by Hosmer-Lemeshow test of goodness of fit,the area under the receiver operating characteristic curve( AUC),and Youden index. Classification accuracy rate and Kappa coefficient were used to confirm the model validation. Results There was no statistically significant difference in behavioral evaluation of overweight/obesity risk evaluation model( low fat intake,fruit and vegetable intake,exercise,and reducing sedentary) between the predicted values and the observed values,the calibration ability was good( χ~2= 9. 19,P = 0. 327),AUC was 0. 75( 0. 72,0. 77,P<0. 001),the optimal cut-off value was 0. 38,the sensitivity and specificity were 0. 61 and 0. 75,respectively. The accurate rate of model was 77. 1%,Kappa value was 0. 48( P<0. 001). The calibration ability of psychological factors in evaluating overweight/obesity risk was poor( χ~2= 19. 26,P = 0. 014). The consistency of predicted results and the actual results of social factors in evaluating overweight/obesity risk was poor( Kappa = 0. 30,P<0. 001). Conclusion Behavioral factors evaluating middle school students’ overweight/obesity risk model has good prediction performance,the optimal cut-off value is 0. 38. Psychological and social factors have impacts on overweight/obesity to a certain extent,but they may not be a direct effect.更多还原