Table 3

Upper 95th percentiles with 95% CI (unweighted values) for bronchodilator responses for whole study population, healthy and COPD subgroups

VariablesStudy populationHealthy SubgroupCOPD GS2+COPD GS2+ (without asthma)
AllMenWomenMen and womenMen and womenMen and women
FEV1-based measuresN1=10 217N1=4826N1=5391N1=3922N1=1009N1=745
 ΔFEV1 (ml)314 (306 to 324)354 (340 to 368)265 (257 to 278)291 (279 to 309)371 (343 to 402)341 (323 to 381)
 ΔFEV1i (%)14.6 (14.1 to 15.3)14.0 (13.2 to 14.6)15.4 (14.5 to 16.0)12.5 (11.9 to 13.2)30.9 (27.8 to 33.8)27.7 (21.6 to 30.9)
 ΔFEV1p (%)10.6 (10.3 to 10.9)10.2 (9.9 to 10.6)10.9 (10.5 to 11.3)10.1 (9.7 to 10.7)13.1 (12.3 to 14.6)12.3 (11.6 to 13.5)
FVC-based measuresN2=9546N2=4560N2=4986N2=3593N2=976N2=723
 ΔFVC (ml)395 (381 to 414)454 (419 to 486)347 (328 to 374)337 (317 to 358)635 (591 to 678)619 (547 to 668)
 ΔFVCi (%)13.3 (12.7 to 13.9)12.6 (11.8 to 13.4)14.1 (13.2 to 15.1)11.2 (10.5 to 12.2)29.4 (26.6 to 31.6)26.7 (24.4 to 30.6)
 ΔFVCp (%)10.8 (10.4 to 11.4)10.4 (9.7 to 10.8)11.6 (10.7 to 12.5)9.6 (9.1 to 10.3)18.0 (17.0 to 19.7)17.3 (15.7 to 18.8)
  • ΔFEV1 (ml) and ΔFVC (ml) are absolute change after bronchodilator; ΔFEV1i and ΔFVCi are change as a per cent of initial value; ΔFEV1p and ΔFVCp are change as per cent of predicted value. N1 is number with non-missing FEV1 values and N2 is number with non-missing FVC values.

  • COPD GS2+ = FEV1/FVC <0.7 and FEV1% predicted<80%; COPD GS2+, without asthma = COPD GS2+ but with no self-reported diagnosis of asthma.

  • In the COPD subgroups, the CIs for individual sites were large due to small sample size (<50).

  • COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.