Abstract
Background: UPLIFT® was a 4-yr, randomized, double-blind, placebo-controlled multicenter trial in 5993 patients (pts) with chronic obstructive pulmonary disease (COPD).
Aims and objectives: To explore spirometry quality and reproducibility in this large trial.
Methods: Within-test variability of pre- and post-bronchodilator (BD) forced expiratory volume in 1s (FEV1) was within-pt measurement error of acceptable maneuvers in 1 spirometry, compared across study visits. Between-test variability was mean difference of best pre- or post-FEV1 values between 2 visits (6 mo interval), corrected for normal decline (-15mL), at trial start (a), middle (b) and end (c).
Results: 3 acceptable maneuvers in 93.8% visits. Within-test variability of pre- and post-FEV1 (mean SD: 0.092L and 0.098L) decreased during the trial (visits 3-19; figure), a similar pattern seen in analysis of pts with measurements at all visits. Between-test variability decreased over time: pre-FEV1 (a=0.14±0.13L; b=0.13±0.12L; c=0.12±0.12L); post-FEV1 (a=0.14±0.14L; b=0.13±0.12L; c=0.12±0.12L), and was dependent on age, sex, smoking status, GOLD stage, but not BD response or treatment (tiotropium/control).
Conclusion: Spirometry quality in UPLIFT® was excellent and improved during the trial. Large intersession variability dependent on age, sex, smoking and COPD severity suggests relevant cut-offs for individual disease monitoring are hard to establish.
Funded by Boehringer Ingelheim/Pfizer
- © 2011 ERS