Annual decline in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) before and after bronchodilator use after withdrawing tiotropium in early chronic obstructive pulmonary disease (COPD)#

Decline per yearp-value
PlaceboTiotropiumDifference (95% CI)
Subjects n126136
 Before bronchodilator use31±2121±2010 (−47–67)0.73
 After bronchodilator use68±1648±1620 (−24–64)0.37
 Before bronchodilator use40±3526±3314 (−80–107)0.77
 After bronchodilator use59±3123±2936 (−46–118)0.39

Data are presented as mean±se, unless otherwise stated. #: values were measured from month 36 until the end of the study (follow-up from 36 to 60 months after withdrawing tiotropium in early COPD). Multiple linear regression was adopted for each follow-up. For each follow-up visit, the measured value was the dependent variable, and covariates included the individual baseline value, baseline smoking status, treatment allocation and participating centre. Additionally, for 36–60 months, the p-value was computed by using the individual baseline value, smoking status across the whole follow-up, bronchiectasis status, treatment allocation and participating centre as covariates; : the difference was calculated as the value in the placebo group minus the value in the tiotropium group.