title: Validation of a one-page patient-reported Charlson comorbidity index questionnaire for upper aerodigestive tract cancer patients.
abstract: OBJECTIVE
  Cancer patients have a wide range of comorbidities that are important confounders for biomarker and clinical studies of prognosis and outcome. Comorbidities can be captured using the Charlson Comorbidity Index (CCI) through abstraction of medical records, but patient-reported outcome (PRO) questionnaires have also been used. The objective was to validate the PRO-CCI in a head and neck cancer (HNC) population, and to assess its level of agreement with the standard (std-CCI) method of chart review.
  
  
  METHODS
  A one-page PRO-CCI was compared with the std-CCI obtained through independent abstraction in 882 HNC patients (2007-2010). Kappa statistics and associated measures (p(pos) and p(neg)) were used to assess agreement. Discrepancy for each comorbid illness was evaluated. Proportional hazard models compared the association of std-CCI and PRO-CCI with overall survival (OS). Adjustments were made and a modified PRO-CCI was re-evaluated in a new cohort of upper aerodigestive tract cancers patient.
  
  
  RESULTS
  PRO-CCI was higher than the std-CCI (p < 0.0001). After adjustment, having at least two comorbidities according to either the std-CCI [HR 1.97 (1.38-2.80)] or the PRO-CCI [HR 1.62 (1.18-2.24)] was prognostic. Of the most prevalent comorbidities, agreement was high for most of the CCI elements (kappa 0.76-0.93), but poorest agreement for connective tissue disease (kappa = 0.29, p(pos) = 43%, p(neg) = 84%) and COPD (kappa = 0.48, p(pos) = 53%, p(neg) = 95%). When the connective tissue disease question was modified, agreement of this item improved (kappa = 0.47, p(pos) = 50%).
  
  
  CONCLUSIONS
  PRO-CCI can be an easy and effective tool in prognostic and outcomes research in HNC patients.
authors.affiliation: Medical Biophysics, Ontario Cancer Institute, 610 University Ave., Toronto, ON, Canada M5G 2M9. steven.habbous@uhn.ca
authors.forename: Steven
authors.initials: S
authors.lastname: Habbous
authors.forename: Karen P
authors.initials: KP
authors.lastname: Chu
authors.forename: Luke T G
authors.initials: LT
authors.lastname: Harland
authors.forename: Anthony
authors.initials: A
authors.lastname: La Delfa
authors.forename: Ehab
authors.initials: E
authors.lastname: Fadhel
authors.forename: Bin
authors.initials: B
authors.lastname: Sun
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Amy
authors.initials: A
authors.lastname: Wong
authors.forename: Doris
authors.initials: D
authors.lastname: Howell
authors.forename: Jolie
authors.initials: J
authors.lastname: Ringash
authors.forename: John
authors.initials: J
authors.lastname: Waldron
authors.forename: Brian
authors.initials: B
authors.lastname: O'Sullivan
authors.forename: David
authors.initials: D
authors.lastname: Goldstein
authors.forename: Shao-Hui
authors.initials: SH
authors.lastname: Huang
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Liu
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000428:Alcohol Drinking; D002294:Carcinoma, Squamous Cell / Q000150:complications*; D015331:Cohort Studies; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D004194:Disease; D004522:Educational Status; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications*; D006801:Humans; D008297:Male; D017533:Marital Status; D008499:Medical Records; D008875:Middle Aged; D009367:Neoplasm Staging; D009790:Occupations; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D057566:Self Report; D012720:Severity of Illness Index; D012907:Smoking; D011795:Surveys and Questionnaires; D015996:Survival Rate