title: Which patients with chronic obstructive pulmonary disease benefit from the addition of an inhaled corticosteroid to their bronchodilator? A cluster analysis.
abstract: OBJECTIVE
  To identify subsets of chronic obstructive pulmonary disease (COPD) patients who are more protected from exacerbations with the use of an inhaled corticosteroid/long-acting β2 agonist (ICS/LABA) combination, compared with the use of LABA monotherapy.
  
  
  METHODS
  Post hoc cluster analysis of patients from two randomised clinical trials of salmeterol/fluticasone propionate (SFC) and salmeterol (SAL) that had primary endpoints of moderate/severe exacerbation rates.
  
  
  METHODS
  Centres in North America.
  
  
  METHODS
  1543 COPD patients were studied.
  
  
  METHODS
  SFC 50/250 µg or SAL 50 µg, twice daily.
  
  
  METHODS
  The analysis identified clusters of COPD patients more responsive to SFC versus SAL with respect to the annual rate of moderate/severe exacerbations and compared their baseline clinical characteristics.
  
  
  RESULTS
  Overall, SFC significantly reduced the annual rate of moderate/severe exacerbations as compared with SAL alone (rate ratio (RR)=0.701, p<0.001). Three-patient clusters were identified: COPD patients receiving diuretics (RR=0.56, p<0.001); patients not receiving diuretics but with forced expiratory volume in 1 s (FEV1) reversibility ≥12% (RR=0.67, p<0.001) exhibited a substantial reduction in the annual rate of moderate/severe exacerbations relative to SAL. A third cluster, consisting of patients not receiving diuretics and without FEV1 reversibility, demonstrated no difference for SFC versus SAL. Patients receiving diuretics had a significantly higher prevalence of comorbid cardiovascular disease.
  
  
  CONCLUSIONS
  COPD patients receiving diuretics and those not receiving diuretics but with FEV1 reversibility >12% at baseline were significantly more likely to experience a reduction in COPD-associated exacerbations with SFC versus SAL alone.
  
  
  BACKGROUND
  NCT00115492, NCT00144911.
authors.affiliation: GlaxoSmithKline, Research Triangle Park, Durham, North Carolina, USA.
authors.forename: Rachael L
authors.initials: RL
authors.lastname: Disantostefano
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: David B
authors.initials: DB
authors.lastname: Rubin
authors.forename: David A
authors.initials: DA
authors.lastname: Stempel