title: β-Blocker use and incidence of chronic obstructive pulmonary disease exacerbations.
abstract: BACKGROUND
  β-Adrenergic antagonist (β-blocker) use in patients with chronic obstructive pulmonary disease (COPD) has been avoided as a result of potential risk of pulmonary adverse effects. However, recent studies indicate that β-blocker use in patients with COPD can decrease outpatient visits and either decrease or have no effect on the number of hospitalizations. Long-term treatment with β-blockers has been shown to increase survival and decrease exacerbations in patients with COPD.
  
  
  OBJECTIVE
  To assess the impact of β-blocker use on the incidence of exacerbations in patients with COPD.
  
  
  METHODS
  In a retrospective cohort study of patients with COPD from 2 academic primary care practice sites who were seen in 2010, patients were identified using International Classification of Diseases, 9th revision, Clinical Modification codes for COPD and reviewing active medication lists for COPD-specific medications (tiotropium). Patients were classified as either a β-blocker user or a nonuser. Primary outcomes were incidence and severity of COPD exacerbations. Secondary outcomes included COPD exacerbations distinguished by β-blocker cardioselectivity and all-cause hospitalizations.
  
  
  RESULTS
  The study enrolled 412 patients. Of those, 166 patients were β-blocker users and 246 were β-blocker nonusers. β-Blocker users were less likely to have a COPD exacerbation (OR 0.61, 95% CI 0.40-0.93) and had fewer mild exacerbations (OR 0.56; 95% CI 0.34-0.89). There was no significant difference in COPD exacerbations based on β-blocker cardioselectivity (OR 0.84, 95% CI 0.38-1.83). When controlled for, using a backwards stepwise logistic regression, β-blocker use was a variable in the model that predicted exacerbations but alone was not statistically significant (adjusted OR 0.62, 95% CI 0.39-1.01).
  
  
  CONCLUSIONS
  Patients with COPD prescribed a β-blocker were significantly less likely to have a COPD exacerbation and had fewer mild COPD exacerbations.
authors.affiliation: University of Tennessee Health Science Center, College of Pharmacy, Knoxville, Tennessee, USA. mfarland@uthsc.edu
authors.forename: Michelle Z
authors.initials: MZ
authors.lastname: Farland
authors.forename: Cassey J
authors.initials: CJ
authors.lastname: Peters
authors.forename: Juli D
authors.initials: JD
authors.lastname: Williams
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Bielak
authors.forename: R Eric
authors.initials: RE
authors.lastname: Heidel
authors.forename: Shaunta' M
authors.initials: SM
authors.lastname: Ray
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002317:Cardiovascular Agents / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D000319:Adrenergic beta-Antagonists; D001993:Bronchodilator Agents; D002317:Cardiovascular Agents