title: Association of control and risk of severe asthma-related events in severe or difficult-to-treat asthma patients.
abstract: BACKGROUND
  Clinical tools for predicting poor outcomes in asthma patients are lacking. This study investigated the association of asthma control and subsequent severe asthma-related healthcare events in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study.
  
  
  METHODS
  The extent of asthma control problems was determined from baseline values of the Asthma Therapy Assessment Questionnaire (ATAQ). Patients self-reported the presence of severe asthma-related events at 6- and 12-month follow up. Poisson regression models determined the adjusted association between baseline control and the likelihood of severe asthma-related events.
  
  
  RESULTS
  At baseline, 2942 patients (mean age, 49.6 years; female, 71.9%) had an ATAQ score (no control problems, 17.0%; 1 control problem, 20.0%; 2 control problems, 30.8%; 3 or 4 control problems, 32.2%) and at least one severe asthma-related event. After adjustment, subjects with three or four control problems were at greater risk for unscheduled office visits [relative risk (RR) = 2.8; 95% confidence interval (CI): 2.4-3.2], course of oral steroids (RR = 2.9; 95% CI: 2.5-3.3), emergency room visits (RR = 4.1; 95% CI: 2.7-6.2) or hospitalization (RR = 13.6; 95% CI: 7.4-24.9), vs no control problems. Progressively poorer levels of asthma control are associated with increasing risk of severe asthma-related events.
  
  
  CONCLUSIONS
  This study provides evidence of an association between poor asthma control and future severe asthma-related healthcare events. A validated questionnaire may help clinicians identify patients requiring intervention to prevent future severe asthma-related events.
authors.affiliation: Pharmaceutical Outcomes Research and Policy Program, Department of Pharmacy, University of Washington, Seattle, WA, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Sullivan
authors.forename: S E
authors.initials: SE
authors.lastname: Wenzel
authors.forename: B W
authors.initials: BW
authors.lastname: Bresnahan
authors.forename: B
authors.initials: B
authors.lastname: Zheng
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: M
authors.initials: M
authors.lastname: Pritchard
authors.forename: T V
authors.initials: TV
authors.lastname: Kamath
authors.forename: S T
authors.initials: ST
authors.lastname: Weiss
mesh_terms: D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D019468:Disease Management; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D018927:Anti-Asthmatic Agents