title: Longitudinal changes in clinical outcomes in older patients with asthma, COPD and asthma-COPD overlap syndrome.
abstract: BACKGROUND
  The progression of obstructive airway diseases (OADs) including asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome in older adults is not well understood.
  
  
  OBJECTIVE
  To examine the prognosis of OADs and to identify potential determinants for longitudinal changes in clinical outcomes.
  
  
  METHODS
  We consecutively recruited 99 older adults (>55 years) with OADs who underwent a multidimensional assessment at baseline and 4 years which involved spirometry, 6-min walk distance (6MWD), assessments of health status (Saint George's Respiratory Questionnaire, SGRQ), comorbidity, and serum and sputum biomarkers. All-cause mortality and respiratory hospitalisation during the follow-up period were recorded. Clinical outcomes were compared between basal and final visits, and changes in clinical outcomes were compared among asthma, COPD and asthma-COPD overlap groups. Associations between clinical parameters, biomarkers and prognosis were examined.
  
  
  RESULTS
  After a median follow-up of 4.2 years, outcome data were available for 75 (75.8%) patients. There were 16 (16.2%) deaths. The BODE index predicted all-cause mortality in older people with OADs. While spirometry, 6MWD and SGRQ deteriorated significantly over the 4 years, there was significant heterogeneity in the longitudinal changes in these clinical outcomes. Participants with COPD had a significant decline in FEV1 (p = 0.003), SGRQ (p = 0.030) and 6MWD [decline of 75.5 (93.4) m, p = 0.024]. The change in 6MWD was lower in the asthma-COPD overlap group. Airflow reversibility was associated with a reduced decline in 6MWD.
  
  
  CONCLUSIONS
  COPD patients had a poor prognosis compared with asthma and asthma-COPD overlap patients. The BODE index is a useful prognostic indicator in older adults with OADs. Both airway disease diagnosis and BODE index warrant specific attention in clinical practice.
authors.affiliation: Priority Research Centre for Asthma and Respiratory Diseases, School of Medicine and Public Health, University of Newcastle, Newcastle, N.S.W., Australia.
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Fu
authors.forename: Peter G
authors.initials: PG
authors.lastname: Gibson
authors.forename: Jodie L
authors.initials: JL
authors.lastname: Simpson
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: McDonald
mesh_terms: D000368:Aged; D001249:Asthma / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D016022:Case-Control Studies; D015331:Cohort Studies; D018450:Disease Progression; D005080:Exercise Test; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D012720:Severity of Illness Index; D013147:Spirometry; D013577:Syndrome