title: Quality and reproducibility of spirometry in COPD patients in a randomized trial (UPLIFT®).
abstract: BACKGROUND
  This study explores spirometry quality and reproducibility in the Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT(®)) trial.
  
  
  METHODS
  Four-year, randomized, double-blind, placebo-controlled, multicenter trial in 5993 patients with chronic obstructive pulmonary disease. Within-test variability of pre- and post-bronchodilator forced expiratory volume in 1 s (FEV(1)) was compared across study visits. Between-test variability of best pre- or post-FEV(1) values between two visits 6 months apart was compared at the start, middle and end of the trial.
  
  
  RESULTS
  Three or more acceptable maneuvers were obtained in 93% of visits. Within-test variability of pre- and post-FEV(1) (mean standard deviation: 0.092 and 0.098 L) decreased during the trial. Between-test variability also decreased: pre-FEV(1) (visit 3-5 = 0.141 ± 0.138 L; visit 9-11 = 0.129 ± 0.121 L; visit 17-19 = 0.121 ± 0.122 L); post-FEV(1) (0.139 ± 0.140, 0.126 ± 0.123, 0.121 ± 0.122 L, respectively), and was dependent on age, sex, smoking status and disease stage, but not on bronchodilator response or study treatment.
  
  
  CONCLUSIONS
  Spirometry quality in UPLIFT(®) was good and improved during the trial. Between-test variability across patient subgroups suggests that relevant cut-offs for individual disease monitoring are difficult to establish.
  
  
  BACKGROUND
  NCT00144339.
authors.affiliation: University Hospital Leuven, Leuven, Belgium. wim.janssens@uzleuven.be
authors.forename: W
authors.initials: W
authors.lastname: Janssens
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Kesten
authors.forename: D P
authors.initials: DP
authors.lastname: Tashkin
authors.forename: B R
authors.initials: BR
authors.lastname: Celli
authors.forename: M
authors.initials: M
authors.lastname: Decramer
mesh_terms: D001993:Bronchodilator Agents / Q000627:therapeutic use*; D018450:Disease Progression; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000503:physiopathology; D015203:Reproducibility of Results; D012602:Scopolamine Derivatives / Q000627:therapeutic use*; D013147:Spirometry / Q000592:standards; D000069447:Tiotropium Bromide; D014797:Vital Capacity / Q000187:drug effects
chemical_list: D001993:Bronchodilator Agents; D012602:Scopolamine Derivatives; D000069447:Tiotropium Bromide
keywords: Forced expiratory volume; Forced vital capacity; Placebo-controlled; Tiotropium