title: Functional comorbidity index in sleep apnea.
abstract: OBJECTIVE
  (1) Measure the association between the Functional Comorbidity Index (range, 0-18) and physical function health status (SF-36 Physical Function domain), general physical health status (SF-36 Physical Component Score), and general mental health status (SF-36 Mental Component Score) outcome measures in a cohort of sleep apnea patients. (2) Test if the Functional Comorbidity Index is more strongly associated (a better predictor) than the well-known Charlson Comorbidity Index (range, 0-37) with these SF-36 outcome measures.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  University of Washington Sleep Center.
  
  
  METHODS
  In a cohort of newly diagnosed obstructive sleep apnea patients (N = 233), we obtained scores for the Functional Comorbidity Index, Charlson Comorbidity Index, and SF-36. We calculated Spearman correlations and adjusted coefficients of determination (R2) with multiple linear regression, adjusted for demographic and health covariates. Bootstrapping generated R2 distributions for statistical comparison.
  
  
  RESULTS
  Functional Comorbidity Index scores (mean ± standard deviation 2.4 ± 1.7) were more widely distributed than Charlson Comorbidity Index scores (0.7 ± 1.4). The Functional Comorbidity Index was significantly correlated with SF-36 Physical Function (-0.53, P < .001), Physical Component Score (-0.44, P < .001), and Mental Component Score (-0.38, P < .001). The Functional Comorbidity Index was a better predictor than the Charlson Comorbidity Index of SF-36 Physical Function (R (2) mean ± standard error 0.27 ± 0.05 vs. 0.17 ± 0.05, P < .001), Physical Component Score (0.23 ± 0.05 vs. 0.17 ± 0.05, P < .001), and Mental Component Score (0.23 ± 0.05 vs. 0.13 ± 0.05, P < .001).
  
  
  CONCLUSIONS
  The Functional Comorbidity Index is a more robust predictor of general health status than the Charlson Comorbidity Index in obstructive sleep apnea patients.
authors.affiliation: Resident Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington, USA.
authors.forename: Corinna G
authors.initials: CG
authors.lastname: Levine
authors.forename: Edward M
authors.initials: EM
authors.lastname: Weaver
mesh_terms: D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D012891:Sleep Apnea Syndromes / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014861:Washington / Q000453:epidemiology
keywords: Charlson Comorbidity Index; Functional Comorbidity Index; comorbidity; health status; physical function; sleep apnea