title: Use of data mining techniques to determine and predict length of stay of cardiac patients.
abstract: OBJECTIVE
  Predicting the length of stay (LOS) of patients in a hospital is important in providing them with better services and higher satisfaction, as well as helping the hospital management plan and managing hospital resources as meticulously as possible. We propose applying data mining techniques to extract useful knowledge and draw an accurate model to predict the LOS of heart patients.
  
  
  METHODS
  Data were collected from patients with coronary artery disease (CAD). The patient records of 4,948 patients who had suffered CAD were included in the analysis. The techniques used are classification with three algorithms, namely, decision tree, support vector machines (SVM), and artificial neural network (ANN). LOS is the target variable, and 36 input variables are used for prediction. A confusion matrix was obtained to calculate sensitivity, specificity, and accuracy.
  
  
  RESULTS
  The overall accuracy of SVM was 96.4% in the training set. Most single patients (64.3%) had an LOS ≤5 days, whereas 41.2% of married patients had an LOS >10 days. Moreover, the study showed that comorbidity states, such as lung disorders and hemorrhage with drug consumption have an impact on long LOS. The presence of comorbidities, an ejection fraction <2, being a current smoker, and having social security type insurance in coronary artery patients led to longer LOS than other subjects.
  
  
  CONCLUSIONS
  All three algorithms are able to predict LOS with various degrees of accuracy. The findings demonstrated that the SVM was the best fit. There was a significant tendency for LOS to be longer in patients with lung or respiratory disorders and high blood pressure.
authors.affiliation: Department of Health Information Management, School of Health Management and Information Sciences, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Peyman Rezaei
authors.initials: PR
authors.lastname: Hachesu
authors.forename: Maryam
authors.initials: M
authors.lastname: Ahmadi
authors.forename: Somayyeh
authors.initials: S
authors.lastname: Alizadeh
authors.forename: Farahnaz
authors.initials: F
authors.lastname: Sadoughi
keywords: Coronary Artery Disease; Data Mining; Extract; Length of Stay; Patients