title: Prognostic value of variables derived from the six-minute walk test in patients with COPD: Results from the ECLIPSE study.
abstract: In addition to the six-min walk distance (6 MWD), other six-min walk test (6 MWT) derived variables, such as mean walk-speed (6MWSpeed), 6-min walk-work (6 MWW), distance-saturation product (DSP), exercise-induced oxygen desaturation (EID), and unintended stops may be useful for the prediction of mortality and hospitalization in patients with chronic obstructive pulmonary disease (COPD). We studied the association between 6 MWT-derived variables and mortality as well as hospitalization in COPD patients and compared it with the BODE index. A three-year prospective study (ECLIPSE) to evaluate the prognostic value of 6 MWT-derived variables in 2010 COPD patients. Cox's proportional-hazard regressions were performed to estimate 3-year mortality and hospitalization. During the follow-up, 193 subjects died and 622 were hospitalized. An adjusted Cox's regression model of hazard ratio [HR] for impaired 6 MWT-derived variables was significant referring to: mortality (6 MWD ≤334 m [2.30], 6MWSpeed ≤0.9 m/sec [2.15], 6 MWW ≤20000 m kg [2.17], DSP ≤290 m% [2.70], EID ≤88% [1.75], unintended stops [1.99]; and hospitalization (6 MWW ≤27000 m kg [1.23], EID ≤88% [1.25], BODE index ≥3 points [1.40]; all p ≤ 0.05). The 6 MWT-derived variables have an additional predictive value of mortality in patients with COPD. The 6 MWW, EID and the BODE index refine the prognosis of hospitalization.
authors.affiliation: Department of Research and Education; CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands. Electronic address: vasilisandrianopoulos@ciro-horn.nl.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Andrianopoulos
authors.affiliation: Department of Research and Education; CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands; Department of Respiratory Medicine, Maastricht University Medical Centre (MUMC+), Maastricht, The Netherlands.
authors.forename: Emiel F M
authors.initials: EF
authors.lastname: Wouters
authors.affiliation: Department of Respiratory Medicine, School of Clinical Science, University of Liverpool, United Kingdom.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Pinto-Plata
authors.affiliation: Department of Research and Education; CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Lowie E G W
authors.initials: LE
authors.lastname: Vanfleteren
authors.affiliation: Department of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Per S
authors.initials: PS
authors.lastname: Bakke
authors.affiliation: Department of Research and Education; CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Frits M E
authors.initials: FM
authors.lastname: Franssen
authors.affiliation: Thorax Institute, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERES, Barcelona, Spain.
authors.forename: Alvar
authors.initials: A
authors.lastname: Agusti
authors.affiliation: University of Edinburgh, Medical Research Council Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: MacNee
authors.affiliation: Pulmonary and Critical Care Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
authors.forename: Stephen I
authors.initials: SI
authors.lastname: Rennard
authors.affiliation: GSK Research and Development, King of Prussia, Philadelphia, PA, USA.
authors.forename: Ruth
authors.initials: R
authors.lastname: Tal-Singer
authors.affiliation: Department of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vogiatzis
authors.affiliation: Department of Respiratory Medicine, Odense University Hospital, Odense, Denmark; Respiratory and Allergy Research Group, Manchester Academic Health Science Center, University of Manchester, Manchester, UK.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Vestbo
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Bartolome R
authors.initials: BR
authors.lastname: Celli
authors.affiliation: Department of Research and Education; CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands; REVAL - Rehabilitation Research Center, BIOMED - Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
authors.forename: Martijn A
authors.initials: MA
authors.lastname: Spruit
mesh_terms: D000328:Adult; D000368:Aged; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D012720:Severity of Illness Index; D014797:Vital Capacity / Q000502:physiology; D016138:Walking / Q000502:physiology
keywords: COPD; Exercise physiology; Exercise testing; Hospitalization; Mortality; Prognostic markers