Cited by 373Chronic Obstructive Pulmonary Disease (COPD) ResearchHealth Systems, Economic Evaluations, Quality of LifeAsthma and respiratory diseases

Interpretation of treatment changes in 6-minute walk distance in patients with COPD

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Puhan, M. A., Mador, M. J., Held, U., Goldstein, R., Guyatt, G. H., Schünemann, H. J.·2008·European Respiratory Journal

Abstract

There is uncertainty about the interpretation of changes in the 6-min walk distance (6MWD) in chronic obstructive pulmonary disease (COPD) patients and whether the minimal important difference (MID) for this useful outcome measure exists. Data were used from nine trials enrolling a wide spectrum of COPD patients with 6MWD at baseline and follow-up and used to determine threshold values for important changes in 6MWD using three distribution-based methods. Anchor-based methods to determine a MID were also evaluated. Data were included of 460 COPD patients with a mean±sd forced expiratory volume in one second (FEV 1) of 39.2±14.1% predicted and 6MWD of 361±112 m at baseline. Threshold values for important effects in 6MWD were between 29 and 42 m, respectively, using the empirical rule effect size and the standardised response mean. The threshold value was 35 m (95% confidence interval 30–42 m) based on the standard error of measurement. Correlations of 6MWD with patient-reported anchors were too low to provide meaningful MID estimates. 6-min walk distance should change by ∼35 m for patients with moderate to severe chronic obstructive pulmonary disease in order to represent an important effect. This corresponds to a 10% change of baseline 6-min walk distance. The low correlations of 6-min walk distance with patient-reported anchors question whether a minimal important difference exists for the 6-min walk distance.

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  • Only the pilot group surpassed all other estimates for the minimum clinically important difference, with a value of 54 m (95% CI 37-71 m).

    “but only the pilot group surpassed all other estimates for the minimum clinically important difference, 30,31 with a value of 54 m (95% CI 37-71 m).32”

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Research works printed but not linked: 3

  1. [23]23. Krauza MA, Alhajhusain A, Khan AI, Shaffer M, Kufel TJ, Mador MJ. Interval compared with continuous exercise training in patients with COPD. Am J Respir Crit Care Med 2006; 173: A220.
  2. [31]31. Sloan JA, Vargas-Chanes D, Kamath CC, et al. Detecting worms, ducks, and elephants: a simple approach for defining clinically relevant effects in quality-of-life mea- sures. Cancer Integrative Med 2003; 1: 41-47.
  3. [47]47. Cockcroft AE, Saunders MJ, Berry G. Randomised con- trolled trial of rehabilitation in chronic respiratory dis- ability. Thorax 1981; 36: 200-203.

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Authors
Puhan, M. A., Mador, M. J., Held, U., Goldstein, R., Guyatt, G. H., & Schünemann, H. J.
Affiliations
  • University Hospital Zurich (CH)
  • University at Buffalo, State University of New York (US)
  • University of Zurich (CH)
  • University of Toronto (CA)
  • McMaster University (CA)
  • Istituti Fisioterapici Ospitalieri (IT)
Venue
European Respiratory Journal
Published
2008-06-11
Volume
32
Issue
3
Pages
637-643
ISSN
  • 0903-1936 (ISSN-L)
  • 1399-3003
OpenAlex
W2041114293
Cited by
373
References
54
Citations by year
2026: 12 · 2025: 9 · 2024: 11 · 2023: 16 · 2022: 19 · 2021: 19 · 2020: 15 · 2019: 8 · 2018: 14 · 2017: 16 · 2016: 20 · 2015: 30 · 2014: 33 · 2013: 33 · 2012: 37
FWCI
23.93
Type
journal article
Language
en
Open access
Locations
  • European Respiratory Journal (publishedVersion)
  • PubMed (publishedVersion)
  • Zurich Open Repository and Archive (University of Zurich) (acceptedVersion)
  • Zurich Open Repository and Archive (University of Zurich) (submittedVersion)
  • Zurich Open Repository and Archive (University of Zurich)
Funders
  • National Science Foundation
  • European Commission
  • Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (115216, 42192, 3233B0/115216/1)
Topics
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Chronic Obstructive Pulmonary Disease (COPD) Research
  • Social Sciences › Economics, Econometrics and Finance › Economics and Econometrics › Health Systems, Economic Evaluations, Quality of Life
  • Health Sciences › Medicine › Physiology › Asthma and respiratory diseases
Keywords
6-minute walk distance, chronic obstructive pulmonary disease, minimal important difference, cut-off values, treatment effect interpretation, standardized response mean, effect size, anchor-based methods, distribution-based methods, exercise capacity
MeSH terms
Aged, Clinical Trials as Topic, Exercise Test, Female, Forced Expiratory Volume, Humans, Male, Middle Aged, Severity of Illness Index, Treatment Outcome, Exercise Tolerance, Pulmonary Disease, Chronic Obstructive

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