title: Finding the best thresholds of FEV1 and dyspnea to predict 5-year survival in COPD patients: the COCOMICS study.
abstract: BACKGROUND
  FEV1 is universally used as a measure of severity in COPD. Current thresholds are based on expert opinion and not on evidence.
  
  
  OBJECTIVE
  We aimed to identify the best FEV1 (% predicted) and dyspnea (mMRC) thresholds to predict 5-yr survival in COPD patients.
  
  
  METHODS
  We conducted a patient-based pooled analysis of eleven COPD Spanish cohorts (COCOMICS). Survival analysis, ROC curves, and C-statistics were used to identify and compare the best FEV1 (%) and mMRC scale thresholds that predict 5-yr survival.
  
  
  RESULTS
  A total of 3,633 patients (93% men), totaling 15,878 person-yrs. were included, with a mean age 66.4 ± 9.7, and predicted FEV1 of 53.8% (± 19.4%). Overall 975 (28.1%) patients died at 5 years. The best thresholds that spirometrically split the COPD population were: mild ≥ 70%, moderate 56-69%, severe 36-55%, and very severe ≤ 35%. Survival at 5 years was 0.89 for patients with FEV1 ≥ 70 vs. 0.46 in patients with FEV1 ≤ 35% (H.R: 6; 95% C.I.: 4.69-7.74). The new classification predicts mortality significantly better than dyspnea (mMRC) or FEV1 GOLD and BODE cutoffs (all p<0.001). Prognostic reliability is maintained at 1, 3, 5, and 10 years. In younger patients, survival was similar for FEV1 (%) values between 70% and 100%, whereas in the elderly the relationship between FEV1 (%) and mortality was inversely linear.
  
  
  CONCLUSIONS
  The best thresholds for 5-yr survival were obtained stratifying FEV1 (%) by ≥ 70%, 56-69%, 36-55%, and ≤ 35%. These cutoffs significantly better predict mortality than mMRC or FEV1 (%) GOLD and BODE cutoffs.
authors.affiliation: Acute Geriatric Care Unit, Internal Medicine Department, Hospital Universitari Mutua de Terrassa, Terrassa, Barcelona, Spain.
authors.forename: Pere
authors.initials: P
authors.lastname: Almagro
authors.affiliation: Asturias Biomedical Research Office, Asturias, Oviedo, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Martinez-Camblor
authors.affiliation: Fundacio de Investigacio Sanitaria de les Illes Balears, Hospital Universitari Son Espases, Balearic Islands, Spain.
authors.forename: Joan B
authors.initials: JB
authors.lastname: Soriano
authors.affiliation: Respiratory Department, Hospital Universitario Miguel Servet, Zaragoza, Spain.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Marin
authors.affiliation: Respiratory Department, Valme University Hospital, Seville, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Alfageme
authors.affiliation: Respiratory Department, Hospital Nuestra Señora de la Candelaria, Tenerife, Spain.
authors.forename: Ciro
authors.initials: C
authors.lastname: Casanova
authors.affiliation: Respiratory Department, Hospital Galdakao-Usansolo, Bizkaia, Spain.
authors.forename: Cristobal
authors.initials: C
authors.lastname: Esteban
authors.affiliation: Respiratory Department, Hospital Arnau de Vilanova,Valencia, Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Soler-Cataluña
authors.affiliation: Respiratory Department, Clínica Universidad de Navarra, Pamplona, Spain.
authors.forename: Juan P
authors.initials: JP
authors.lastname: de-Torres
authors.affiliation: Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard University, Boston, Massachusetts, United States of America.
authors.forename: Bartolome R
authors.initials: BR
authors.lastname: Celli
authors.affiliation: Pneumology Department, Hospital Universitari Vall d'Hebron, CIBER de Enfermedades Respiratorias (CIBERES), Barcelona, Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: Miravitlles
mesh_terms: D000368:Aged; D019540:Area Under Curve; D015331:Cohort Studies; D004417:Dyspnea / Q000175:diagnosis*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology*; D012307:Risk Factors; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology; D013147:Spirometry; D016019:Survival Analysis