Objective To introduce classification tree model to analyze the effects of environmental risk factors on childhood acute lymphoblastic leukemia (ALL), screen the environmental risk factors, and provide scientific references for ALL prevention.
Methods A case-control survey was conducted using questionnaires to retrospectively collect information on 30 substantial environmental risk factors among 315 children (179 ALL children as case group, 136 healthy children as control group).Classification tree model was built using chi-square automatic interaction detection (CHAID) method.The application value of final model was evaluated by gain diagram, index chart, and receiver operating characteristic (ROC) curve.
Results The classification tree model contained four stratum and eleven nodes.Five explanatory variables for childhood ALL were screened out from the model including children not eating vegetables and fruits (χ2=47.070, P<0.001), children being exposed to paint (χ2=8.403, P=0.004), and maternal medication use (χ2=13.638, P<0.001), secondhand smoke exposure (χ2=8.803, P=0.003), and catching a cold during pregnant (χ2=8.650, P=0.003).The area under the ROC curve was 0.781, which was significantly different from 0.5 (P<0.001), indicating that the final classification tree model fit well.
Conclusion Several environmental risk factors could be related to childhood ALL.
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