title: Fatigue as a Driver of Overall Quality of Life in Cancer Patients.
abstract: BACKGROUND
  This manuscript describes an approach for analyzing large amounts of disparate clinical data to elucidate the most impactful factor(s) that relate to a meaningful clinical outcome, in this case, the quality of life of cancer patients. The relationships between clinical and quality of life variables were evaluated using the EORTC QLQ-C30 global health domain--a validated surrogate variable for overall cancer patient well-being.
  
  
  METHODS
  A cross-sectional study design was used to evaluate the determinants of global health in cancer patients who initiated treatment at two regional medical centers between January 2001 and December 2009. Variables analyzed included 15 EORTC QLQ-C30 scales, age at diagnosis, gender, newly diagnosed/ recurrent disease status, and stage. The decision tree algorithm, perhaps unfamiliar to practicing clinicians, evaluates the relative contribution of individual parameters in classifying a clinically meaningful functional endpoint, such as the global health of a patient.
  
  
  RESULTS
  Multiple patient characteristics were identified as important contributors. Fatigue, in particular, emerged as the most prevalent indicator of cancer patients' quality of life in 16/23 clinically relevant subsets. This analysis allowed results to be stated in a clinically-intuitive, rule set format using the language and quantities of the Quality of Life (QoL) tool itself.
  
  
  CONCLUSIONS
  By applying the classification algorithms to a large data set, identification of fatigue as a root factor in driving global health and overall QoL was revealed. The ability to practice mining of clinical data sets to uncover critical clinical insights that are immediately applicable to patient care practices is illustrated.
authors.affiliation: Medicine & Science, Cancer Treatment Centers of America, Zion, Illinois, United States of America.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: McCabe
authors.affiliation: Medicine & Science, Cancer Treatment Centers of America, Zion, Illinois, United States of America; Department of Epidemiology, University of Illinois School of Public Health, Chicago, Illinois, United States of America.
authors.forename: James F
authors.initials: JF
authors.lastname: Grutsch
authors.affiliation: Medicine & Science, Cancer Treatment Centers of America, Zion, Illinois, United States of America.
authors.forename: Donald P
authors.initials: DP
authors.lastname: Braun
authors.affiliation: Medicine & Science, Cancer Treatment Centers of America, Zion, Illinois, United States of America.
authors.forename: Swetha B
authors.initials: SB
authors.lastname: Nutakki
mesh_terms: D003663:Decision Trees; D003710:Demography; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009369:Neoplasms / Q000503:physiopathology*; D011788:Quality of Life