Decision Trees for Detection of Activity Intensity in Youth with Cerebral Palsy.
Decision Trees for Detection of Activity Intensity in Youth with Cerebral Palsy.
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DOI：
10.1249/mss.0000000000000842
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发表时间：
2016-05
影响因子：
4.1
通讯作者：
O'Neil ME
中科院分区：
文献类型：
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作者：
Trost SG;Fragala-Pinkham M;Lennon N;O'Neil ME
开发和测试决策树（DT）模型，以根据加速计输出和粗大运动功能分类系统（GMFCS）分类水平对患有脑瘫（CP）的非卧床青少年的身体活动（PA）强度进行分类; 2）将新DT模型的分类准确性与先前发表的CP青少年截点进行比较。患有CP的青少年（GMFCS水平I-III）（N=51）在佩戴便携式代谢系统和ActiGraph GT 3X加速度计的同时，完成了7项PA强度增加的活动试验。DT模型用于识别与久坐（SED）（< 1.5 MET）、轻度PA（LPA）（≥1.5且<3 MET）和中度至剧烈PA（MVPA）（≥ 3 MET）对应的垂直轴（VA）和向量幅度（VM）计数阈值。使用R中的“rpart”和“caret”包对模型进行训练和交叉验证。对于VA（VA_DT）和VM决策树（VM_DT），单个阈值区分LPA和SED，而区分MVPA和LPA的阈值随着损伤水平的增加而降低。VC_DT的平均交叉验证准确度分别为81.1%，76.7%和82.9%，GMFCS水平I，II和III。VM_DT的相应交叉验证准确率分别为80.5%、75.6%和84.2%。在每个GMFCS水平，DT模型实现了更好的PA强度识别比以前公布的临界点。准确性差异在GMFCS III级参与者中最大，其中先前发表的临界点错误分类了40%的MVPA活性试验。GMFCS特异性临界点提供了更准确的评估MVPA水平的青年CP在整个频谱的走动能力。
To develop and test decision tree (DT) models to classify physical activity (PA) intensity from accelerometer output and Gross Motor Function Classification System (GMFCS) classification level in ambulatory youth with cerebral palsy (CP); and 2) compare the classification accuracy of the new DT models to that achieved by previously published cut-points for youth with CP. Youth with CP (GMFCS Levels I - III) (N=51) completed seven activity trials with increasing PA intensity while wearing a portable metabolic system and ActiGraph GT3X accelerometers. DT models were used to identify vertical axis (VA) and vector magnitude (VM) count thresholds corresponding to sedentary (SED) (< 1.5 METs), light PA (LPA) (≥1.5 and <3 METs) and moderate-to-vigorous PA (MVPA) (≥ 3 METs). Models were trained and cross-validated using the “rpart” and “caret” packages within R. For the VA (VA_DT) and VM decision trees (VM_DT), a single threshold differentiated LPA from SED, while the threshold for differentiating MVPA from LPA decreased as the level of impairment increased. The average cross-validation accuracy for the VC_DT was 81.1%, 76.7%, and 82.9% for GMFCS levels I, II, and III, respectively. The corresponding cross-validation accuracy for the VM_DT was 80.5%, 75.6%, and 84.2%, respectively. Within each GMFCS level, the DT models achieved better PA intensity recognition than previously published cut-points. The accuracy differential was greatest among GMFCS level III participants, in whom the previously published cut-points misclassified 40% of the MVPA activity trials. GMFCS-specific cut-points provide more accurate assessments of MVPA levels in youth with CP across the full spectrum of ambulatory ability.