title: Disability and health care costs in the Medicare population.
abstract: OBJECTIVE
  To determine the effect of activity limitations on health care expenditures.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  National survey.
  
  
  METHODS
  Data from the 1997 Medicare Current Beneficiary Survey (n=9298), a nationally representative sample of community-dwelling Medicare beneficiaries who were older than 64 years of age.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The impact of patient disability on health care costs (inpatient, outpatient, skilled nursing facility, home health, medications). Activity limitations were determined by patient assessment of restrictions in activities of daily living (ADLs).
  
  
  RESULTS
  Over 20% (n=6,500,000) of the entire Medicare population had at least 1 health-related activity limitation. Total median health care costs per year (interquartile range [IQR]) increased as the number of these limitation increased (0 ADLs: $1934 [IQR, $801-$4761]; 1-2 ADLs: $4540 [IQR, $1744-$12,937]; 3-4 ADLs: $7589 [IQR, $2580-$23,149]; 5-6 ADLs: $14,399 [IQR, $5425-$33,014]). After adjusting for confounding characteristics including the impact of comorbid illnesses, Medicare enrollees incurred higher health care costs as their number of activity limitations increased (0 ADLs: cost ratio=1.0; 1-2 ADLs: cost ratio=1.4 [95% confidence interval (CI), 1.2-1.6]; 3-4 ADLs: cost ratio=1.6 [95% CI, 1.3-2.0]; 5-6 ADLs: cost ratio=2.3 [95% CI, 1.7-3.2]). The cost increases were because of an increase in the frequency of all events (eg, hospital admissions, outpatient visits) rather than an increase in the intensity or cost of those events. In addition, with increasing activity limitations, there was a significant increase in the proportional impact of home health costs such that, for those with 5 or 6 limitations, home health costs exceeded the cost of outpatient visits.
  
  
  CONCLUSIONS
  Activity limitation is an independent risk factor for increased health care costs and appears to be more than just a proxy for chronic illness.
authors.affiliation: Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA. leighton@u.washington.edu
authors.forename: Leighton
authors.initials: L
authors.lastname: Chan
authors.forename: Shelli
authors.initials: S
authors.lastname: Beaver
authors.forename: Richard F
authors.initials: RF
authors.lastname: Maclehose
authors.forename: Amitabh
authors.initials: A
authors.lastname: Jha
authors.forename: Matthew
authors.initials: M
authors.lastname: Maciejewski
authors.forename: Jason N
authors.initials: JN
authors.lastname: Doctor
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D015897:Comorbidity; D003430:Cross-Sectional Studies; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D017048:Health Care Costs; D006801:Humans; D016014:Linear Models; D008297:Male; D006278:Medicare / Q000191:economics*; D012307:Risk Factors; D014481:United States