title: Correlation between symptoms and function in older adults with comorbidity.
abstract: OBJECTIVE
  To describe the relationship between symptom scores and mobility function measures, assess whether symptom scores and disease scores are similarly associated with mobility function, and identify clusters of symptoms that are most strongly associated with functional status in older adults.
  
  
  METHODS
  Secondary analysis of cross-sectional data from three cohorts.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  One hundred ninety-five community-dwelling subjects with poor flexibility or cardiorespiratory fitness (fitness cohort), 211 female retirement community residents with vertebral fractures (VF cohort), and 61 subjects with Parkinson's disease (PD cohort).
  
  
  METHODS
  Twenty-item self-reported symptom scale, 17-item self-reported disease scale, Medical Outcomes Study 36-item Short Form Survey (SF-36) Physical Functioning Scale, 5-item Nagi Disability scale, 10-m walk time, supine to stand time.
  
  
  RESULTS
  Symptom scores correlated with mobility function measures (Spearman correlation coefficients ranged from 0.222 to 0.509) at least as strongly as, if not more strongly than, did disease scores. Symptom scores remained associated with functional outcomes after controlling for disease score and demographic variables. Adding symptom scores to models that contained disease scores significantly increased the association with functional outcomes. In the fitness cohort, muscle weakness was the most explanatory single symptom, associated with an average decrease of 17.8 points on the Physical Functioning Scale. A model that included only muscle weakness, pain, and shortness of breath accounted for 21.2% of the variability in the Physical Functioning Score.
  
  
  CONCLUSIONS
  Symptoms represent useful indicators of disability burden in older adults and are promising targets for interventions to improve function in medically complex patients.
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina 27710, USA. heather.whitson@duke.edu
authors.forename: Heather E
authors.initials: HE
authors.lastname: Whitson
authors.forename: Linda L
authors.initials: LL
authors.lastname: Sanders
authors.forename: Carl F
authors.initials: CF
authors.lastname: Pieper
authors.forename: Miriam C
authors.initials: MC
authors.lastname: Morey
authors.forename: Eugene Z
authors.initials: EZ
authors.lastname: Oddone
authors.forename: Deborah T
authors.initials: DT
authors.lastname: Gold
authors.forename: Harvey Jay
authors.initials: HJ
authors.lastname: Cohen
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities; D005260:Female; D015577:Geriatric Assessment; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D010300:Parkinson Disease / Q000503:physiopathology; D010809:Physical Fitness; D016012:Poisson Distribution; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D016059:Range of Motion, Articular; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires