title: Lung function decline rates according to GOLD group in patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Since the Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups A-D were introduced, the lung function changes according to group have been evaluated rarely.
  
  
  OBJECTIVE
  We investigated the rate of decline in annual lung function in patients categorized according to the 2014 GOLD guidelines.
  
  
  METHODS
  Patients with COPD included in the Korean Obstructive Lung Disease (KOLD) prospective study, who underwent yearly postbronchodilator spirometry at least three times, were included. The main outcome was the annual decline in postbronchodilator forced expiratory volume in 1 second (FEV1), which was analyzed by random-slope and random-intercept mixed linear regression.
  
  
  RESULTS
  A total 175 participants were included. No significant postbronchodilator FEV1 decline was observed between the groups (-34.4±7.9 [group A]; -26.2±9.4 [group B]; -22.7±16.0 [group C]; and -24.0±8.7 mL/year [group D]) (P=0.79). The group with less symptoms (-32.3±7.2 vs -25.0±6.5 mL/year) (P=0.44) and the low risk group (-31.0±6.1 vs -23.6±7.7 mL/year) (P=0.44) at baseline showed a more rapid decline in the postbronchodilator FEV1, but the trends were not statistically significant. However, GOLD stages classified by FEV1 were significantly related to the annual lung function decline.
  
  
  CONCLUSIONS
  There was no significant difference in lung function decline rates according to the GOLD groups. Prior classification using postbronchodilator FEV1 predicts decline in lung function better than does the new classification.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Joohae
authors.initials: J
authors.lastname: Kim
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
authors.forename: Ho Il
authors.initials: HI
authors.lastname: Yoon
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Yeon-Mok
authors.initials: YM
authors.lastname: Oh
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seong Yong
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Republic of Korea.
authors.forename: Tae-Hyung
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Sang Yeub
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea.
authors.forename: Jin Hwa
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang-Do
authors.initials: SD
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012720:Severity of Illness Index; D013147:Spirometry / Q000379:methods*
keywords: GOLD 2014; annual lung function decline; chronic obstructive pulmonary disease