title: Functional Comorbidity Index in chronic rhinosinusitis.
abstract: BACKGROUND
  The Functional Comorbidity Index is a promising tool to predict general health status and adjust for comorbidity confounding in outcomes studies of chronic conditions, but it has been tested as a predictor of general health status only in a sleep apnea cohort. We tested it in a chronic rhinosinusitis cohort with 2 objectives: (1) measure the association between the Functional Comorbidity Index (range, 0 to 18) and general health status (SF-36 Physical Component Score and Mental Component Score); and (2) test if the Functional Comorbidity Index is more strongly associated (a better predictor) than the well-known Charlson Comorbidity Index (range, 0 to 37) with these SF-36 outcome measures.
  
  
  METHODS
  In a cross-sectional study of chronic rhinosinusitis patients, we obtained scores for the Functional Comorbidity Index, Charlson Comorbidity Index, and the SF-36. We calculated Spearman correlations and adjusted coefficients of determination (R(2)) using multiple linear regression, adjusted for demographic covariates. Bootstrapping generated R(2) distributions for statistical comparison.
  
  
  RESULTS
  In the cohort (N = 97), the Functional Comorbidity Index scores (mean ± standard deviation: 2.2 ± 1.9) were more widely distributed than Charlson Comorbidity Index scores (0.6 ± 1.2). The Functional Comorbidity Index significantly correlated with the SF-36 Physical Component Score (-0.49, p < 0.001) and Mental Component Score (-0.37, p < 0.001). The Functional Comorbidity Index was a better predictor than the Charlson Comorbidity Index of SF-36 Physical Component Score (R(2) mean ± standard error: 0.21 ± 0.09 vs 0.15 ± 0.05; p < 0.001) and Mental Component Score (0.16 ± 0.10 vs 0.01 ± 0.06; p < 0.001).
  
  
  CONCLUSIONS
  The Functional Comorbidity Index is a more robust predictor of general health status than the Charlson Comorbidity Index in chronic rhinosinusitis patients.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, WA.
authors.forename: Corinna G
authors.initials: CG
authors.lastname: Levine
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, WA.
authors.forename: Greg E
authors.initials: GE
authors.lastname: Davis
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, WA.|Surgery Service, Department of Veterans Affairs Medical Center, Seattle, WA.
authors.forename: Edward M
authors.initials: EM
authors.lastname: Weaver
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012220:Rhinitis / Q000453:epidemiology*; D057566:Self Report; D012852:Sinusitis / Q000453:epidemiology*; D055815:Young Adult
keywords: comorbidity; confounding factors; health status; outcomes research; sinusitis