title: Classifying smoking urges via machine learning.
abstract: OBJECTIVE
  Smoking is the largest preventable cause of death and diseases in the developed world, and advances in modern electronics and machine learning can help us deliver real-time intervention to smokers in novel ways. In this paper, we examine different machine learning approaches to use situational features associated with having or not having urges to smoke during a quit attempt in order to accurately classify high-urge states.
  
  
  METHODS
  To test our machine learning approaches, specifically, Bayes, discriminant analysis and decision tree learning methods, we used a dataset collected from over 300 participants who had initiated a quit attempt. The three classification approaches are evaluated observing sensitivity, specificity, accuracy and precision.
  
  
  RESULTS
  The outcome of the analysis showed that algorithms based on feature selection make it possible to obtain high classification rates with only a few features selected from the entire dataset. The classification tree method outperformed the naive Bayes and discriminant analysis methods, with an accuracy of the classifications up to 86%. These numbers suggest that machine learning may be a suitable approach to deal with smoking cessation matters, and to predict smoking urges, outlining a potential use for mobile health applications.
  
  
  CONCLUSIONS
  In conclusion, machine learning classifiers can help identify smoking situations, and the search for the best features and classifier parameters significantly improves the algorithms' performance. In addition, this study also supports the usefulness of new technologies in improving the effect of smoking cessation interventions, the management of time and patients by therapists, and thus the optimization of available health care resources. Future studies should focus on providing more adaptive and personalized support to people who really need it, in a minimum amount of time by developing novel expert systems capable of delivering real-time interventions.
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Benedum Hall, Pittsburgh, PA 15260, USA.
authors.forename: Antoine
authors.initials: A
authors.lastname: Dumortier
authors.affiliation: Department of Psychiatry, University of Pittsburgh, 5115 Centre Avenue, Suite 140, Pittsburgh, PA 15232, USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: Beckjord
authors.affiliation: Department of Psychology, University of Pittsburgh, 510 BELPB, 130 N. Bellefield Avenue, Pittsburgh, PA 15260, USA.
authors.forename: Saul
authors.initials: S
authors.lastname: Shiffman
authors.affiliation: Department of Electrical and Computer Engineering, University of Pittsburgh, Benedum Hall, Pittsburgh, PA 15260, USA. Electronic address: esejdic@ieee.org.
authors.forename: Ervin
authors.initials: E
authors.lastname: Sejdić
mesh_terms: D000465:Algorithms; D001499:Bayes Theorem; D006801:Humans; D000069550:Machine Learning; D008962:Models, Theoretical; D012907:Smoking
keywords: Feature selection; Machine learning; Smoking cessation; Smoking urges; Supervised learning