title: Disability and recovery of independent function in obstructive lung disease: the cardiovascular health study.
abstract: BACKGROUND
  Chronic obstructive lung disease frequently leads to disability. Older patients may experience transitions between states of disability and independence over time.
  
  
  OBJECTIVE
  To identify factors associated with transition between states of disability and independent function in obstructive lung disease.
  
  
  METHODS
  We analyzed data on 4,394 participants in the Cardiovascular Health Study who completed prebronchodilator spirometry. We calculated the 1-year probability of developing and resolving impairment in ≥1 instrumental activity of daily living (IADL) or ≥1 activity of daily living (ADL) using transition probability analysis. We identified factors associated with resolving disability using relative risk (RR) regression.
  
  
  RESULTS
  The prevalence of IADL impairment was higher with moderate (23.9%) and severe (36.9%) airflow obstruction compared to normal spirometry (22.5%; p < 0.001). Among participants with severe airflow obstruction, 23.5% recovered independence in IADLs and 40.5% recovered independence in ADLs. In the adjusted analyses, airflow obstruction predicted the development of IADL, but not ADL impairment. Participants with severe airflow obstruction were less likely to resolve IADL impairment [RR 0.67 and 95% confidence interval (CI) 0.49-0.94]. Compared to the most active individuals (i.e. who walked ≥28 blocks per week), walking less was associated with a decreased likelihood of resolving IADL impairment (7-27 blocks: RR 0.81 and 95% CI 0.69-0.86 and <7 blocks: RR 0.73 and 95% CI 0.61-0.86). Increased strength (RR 1.16 and 95% CI 1.05-1.29) was associated with resolving IADL impairment.
  
  
  CONCLUSIONS
  Disability is common in older people, especially in those with severe airflow obstruction. Increased physical activity and muscle strength are associated with recovery. Research is needed on interventions to improve these factors among patients with obstructive lung disease and disability.
authors.affiliation: Health Services Research and Development, Department of Veterans Affairs, Seattle, Wash., USA.
authors.forename: Vincent S
authors.initials: VS
authors.lastname: Fan
authors.forename: Emily R
authors.initials: ER
authors.lastname: Locke
authors.forename: Paula
authors.initials: P
authors.lastname: Diehr
authors.forename: Anthony
authors.initials: A
authors.lastname: Wilsdon
authors.forename: Paul
authors.initials: P
authors.lastname: Enright
authors.forename: Sachin
authors.initials: S
authors.lastname: Yende
authors.forename: Mark
authors.initials: M
authors.lastname: Avdalovic
authors.forename: Graham
authors.initials: G
authors.lastname: Barr
authors.forename: Vishesh K
authors.initials: VK
authors.lastname: Kapur
authors.forename: Rachel
authors.initials: R
authors.lastname: Thomas
authors.forename: Jerry A
authors.initials: JA
authors.lastname: Krishnan
authors.forename: Gina
authors.initials: G
authors.lastname: Lovasi
authors.forename: Stephen
authors.initials: S
authors.lastname: Thielke
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000072038:Cardiac Rehabilitation; D002318:Cardiovascular Diseases / Q000150:complications; D004185:Disability Evaluation; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D057187:Independent Living / Q000706:statistics & numerical data*; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D053580:Muscle Strength; D017063:Outcome Assessment, Health Care; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation; D020127:Recovery of Function; D018570:Risk Assessment; D012720:Severity of Illness Index; D013147:Spirometry; D014481:United States