title: Reanalysis of the Japanese experience using the combined COPD assessment of the 2011 GOLD classification.
abstract: BACKGROUND
  The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 consensus report proposed a new classification system, incorporating symptoms with future risk, in subjects with chronic obstructive pulmonary disease (COPD). We hypothesized it could be applied to Japanese COPD patients.
  
  
  METHODS
  We previously analyzed clinical factors related to 5-year mortality in 150 male outpatients with COPD. We reviewed the data and reanalyzed the relationships between the new GOLD classification and various outcomes including mortality.
  
  
  RESULTS
  There were 51 (34.0%), 12 (8.0%), 57 (38.0%), and 30 (20.0%) patients in GOLD A (forced expiratory volume in 1s [FEV1] ≥ 50% predicted and modified Medical Research Council [mMRC] 0-1), GOLD B (FEV1 ≥ 50% predicted and mMRC ≥ 2), GOLD C (FEV1<50% predicted and mMRC 0-1), and GOLD D (FEV1 <50% predicted and mMRC ≥ 2), respectively. The GOLD 2011 classification correlated significantly with exercise capacity and multi-dimensional disease staging. Cox proportional hazards analysis revealed that, among several methods categorizing symptoms, the GOLD A-D classification was significantly associated with mortality (p=0.0055).
  
  
  CONCLUSIONS
  Although the relative number of patients in each category of the combined COPD assessment classification depended on the choice of symptom measures, the categories defined by the mMRC scale (score 0-1 versus ≥ 2) were most useful for future risk assessed as mortality. GOLD A had the lowest mortality, followed by GOLD B and C, and D had the highest mortality. Exercise capacity was also stratified by the new GOLD classification.
authors.affiliation: Department of Pulmonary Medicine, National Center for Geriatrics and Gerontology, Obu, Japan. Electronic address: koichi-nishimura@nifty.com.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Department of Respiratory Care and Sleep Control Medicine, Graduate School of Medicine, Kyoto University, 54, Kawahara, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. Electronic address: ogato@kuhp.kyoto-u.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Oga
authors.affiliation: Department of Respiratory Medicine, Hikone Municipal Hospital, Hikone, Japan. Electronic address: tsukino@municipal-hp.hikone.shiga.jp.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Tsukino
authors.affiliation: Department of Respiratory Medicine, Tenri Hospital, Tenri, Japan. Electronic address: takhaj@gmail.com.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hajiro
authors.affiliation: Department of Respiratory Medicine, Nishi-Kobe Medical Center, Kobe, Japan. Electronic address: akikeda@nmc-kobe.org.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ikeda
authors.affiliation: Division of Clinical Science, St. George's Hospital Medical School, London, England, UK. Electronic address: pjones@sgul.ac.uk.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
mesh_terms: D000368:Aged; D044466:Asian People; D015331:Cohort Studies; D015444:Exercise; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification* / Q000401:mortality* / Q000503:physiopathology; D012306:Risk; D011795:Surveys and Questionnaires
keywords: COPD Assessment Test; Chronic obstructive pulmonary disease; Global Initiative for Chronic Obstructive Lung Disease; Mortality; St. George's Respiratory Questionnaire