RESUMO
OBJECTIVE: Predictions of hospital charges for cancer patients are very important, because they provide a basis for allocating medical resources in the hospital and for establishing national medical policies. But previous studies to predict hospital charges were mainly based on statistical analysis, which has used only a small aspect among huge medical data so that the prediction power was limited. Thus we developed four data mining models, including two artificial neural network (ANN) models and two classification and regression tree (CART) models, to predict both the total amount of hospital charges and the amount paid by the insurance of cancer patients and compared their efficacies. METHODS:The data was generated from400,625 medical records of 1,605 cancer patients who had been hospitalized toKyungHeeUniversityHospital fromMarch 1, 2003 to February 29, 2004. Clementine 8.1 programwas used to build four data mining prediction models, two for the total amount and two for the amount paid by insurance. The variables included all of the data fields of standard medical record form of Korea. The neural network model used feed-forward back propagation method, which had 2 hidden layers. For decision tree model, RELIEFF method was used and the maximum tree depth was set to 30.We divided the dataset into 67%of training dataset and 33%of test dataset, using stratified sampling. Linear correlation coefficient and gain chart were compared. RESULTS: The ANN models showed better linear correlation coefficient than the CART models in predicting both the total amount (0.824 vs. 0.791) and the amount paid by insurance (0.838 vs. 0.699). The estimated accuracy of ANN model was more than 98%to predict both total amount and amount paid by insurance. The CART model for total amount showed that the relative importance of the variables were duration of admission(0.073), number of consultation(0.061), and treatment group 16(0.06). The CART model for the amount paid by insurance showed that the relative importance of the cariables were duration of admission (0.09), number of ICUadmission (0.063), and number of consultations (0.062). The percent gain of ANN model shows better %gain than CART to predict total amount but to predict amount paid by insurance, ANN showed similar pattern to CART CONCLUSION: The ANNmodels showed better prediction accuracy than CART models. However, the CART models, which serve different information from ANN model, can be used to allocate limited medical resources effectively and efficiently. For the purpose of establishing medical policies and strategies, using those models together is warranted.