title: Effect of theophylline on the rate of moderate to severe exacerbations among patients with chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  To determine the effectiveness of theophyllines in real clinical practice on moderate to severe exacerbations.
  
  
  METHODS
  A cohort of 36,492 chronic obstructive pulmonary disease (COPD) patients aged > or =50 years was reconstructed from the health administrative databases of the province of Quebec, Canada, between 1 January 1995 and 31 December 2002 to compare users of theophyllines with users of inhaled corticosteroids (ICS) and users of long-acting beta(2)-agonists (LABA) on their rate of moderate to severe COPD exacerbations.
  
  
  RESULTS
  Users of theophyllines were found to be less likely than users of LABA [crude rates 84 vs. 91 per 100 patient-years, adjusted rate ratio (RR) 0.89, 95% confidence interval (CI) 0.84, 0.95] and users of theophyllines plus ICS were found to be less likely than users of LABA plus ICS (crude rates 114 vs. 112 per 100 patient-years, adjusted RR 0.89, 95% CI 0.87, 0.92) to have moderate to severe COPD exacerbations. Users of theophyllines were found to be more likely than users of ICS to have a COPD exacerbation (crude rates 84 vs. 77 per 100 patient-years, adjusted RR 1.07, 95% CI 1.04, 1.10), and this association was even stronger among patients who had at least three exacerbations in the year prior to cohort entry (crude rates 273 vs. 213 per 100 patient-years, adjusted RR 1.28, 95% CI 1.19, 1.38).
  
  
  CONCLUSIONS
  The use of theophyllines was found to be associated with a reduction in the rate of COPD exacerbations among all COPD patients, but to be less effective than ICS among patients with frequent exacerbations.
authors.affiliation: Faculty of Pharmacy, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Marie-Christyne
authors.initials: MC
authors.lastname: Cyr
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Beauchesne
authors.forename: Catherine
authors.initials: C
authors.lastname: Lemière
authors.forename: Lucie
authors.initials: L
authors.lastname: Blais
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D011792:Quebec; D012044:Regression Analysis; D012720:Severity of Illness Index; D013806:Theophylline / Q000627:therapeutic use*
chemical_list: D001993:Bronchodilator Agents; D013806:Theophylline