title: Asthma control, severity, and quality of life: quantifying the effect of uncontrolled disease.
abstract: BACKGROUND
  Current practice guidelines emphasize the importance of attaining asthma control. We sought to quantify the degree of quality-of-life impairment associated with different levels of asthma control.
  
  
  METHODS
  We analyzed prospective data for 987 adults in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. Asthma control was assessed by using the Asthma Therapy Assessment Questionnaire, a validated index of control problems ranging from 0 to 4. Disease-specific quality of life and preference-based health utilities were assessed after 12 months of follow-up by using the Mini-Asthma Quality of Life Questionnaire (AQLQ) and EuroQoL 5-D (EQ-5D). We used multiple linear regression to model the relationship between asthma control and the AQLQ and EQ-5D while controlling for severity classification and lung function.
  
  
  RESULTS
  Asthma control varied widely, even within a population with predominantly moderate-to-severe disease. An inverse relationship was observed between the number of asthma control problems and quality of life. Specifically, poorer control at baseline predicted worse AQLQ and EQ-5D scores at follow-up. Asthma control remained an independent predictor of disease-specific quality of life and general health in multivariate models and was a better longitudinal predictor of health status than asthma severity at baseline.
  
  
  CONCLUSIONS
  Poor asthma control is associated with a substantial degree of impairment and predicts quality of life at 12 months, even after taking baseline asthma severity into account.
  
  
  CONCLUSIONS
  Self-assessed measures of asthma control might help to identify and manage those patients at greatest risk for future health impairment.
authors.affiliation: Department of Medicine, the University of California San Francisco, USA. hubert.chen@ucsf.edu
authors.forename: Hubert
authors.initials: H
authors.lastname: Chen
authors.forename: Michael K
authors.initials: MK
authors.lastname: Gould
authors.forename: Paul D
authors.initials: PD
authors.lastname: Blanc
authors.forename: Dave P
authors.initials: DP
authors.lastname: Miller
authors.forename: Tripthi V
authors.initials: TV
authors.lastname: Kamath
authors.forename: June H
authors.initials: JH
authors.lastname: Lee
authors.forename: Sean D
authors.initials: SD
authors.lastname: Sullivan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome