title: Classification of patients with chronic obstructive pulmonary disease according to the Latin American Thoracic Association (ALAT) staging systems and the global initiative for chronic obstructive pulmonary disease (GOLD).
abstract: BACKGROUND
  Several classification systems use different criteria when assessing COPD stages. The objective of this study was to compare the prevalence and distribution of COPD stagesusing Global initiative for chronic Obstructive Lung Disease (GOLD) recommendationsand Latin American Thoracic Association (ALAT) guidelinesin a primary-care population.
  
  
  METHODS
  Subjects attending routine primary care visits, ≥40 years of age, current or former smokers or exposed to biomass, completed a questionnaire and performed spirometry. COPD was defined as post-bronchodilator FEV1/FVC<0.70 and categorised according to GOLD-2013 criteria and ALAT-2014 guideline. The BODEx index was used to assess the prognostic value of the stratification systems.
  
  
  RESULTS
  A total of 1743 subjects completed the interview, 1540 performed acceptable spirometry. COPD prevalence according GOLD-2013 was 20.1% and had a U-shaped stage distribution (group A: 9.3%, B: 4.3%, C: 2.0%, D: 4.6%). According to ALAT, prevalence was 19.7% with a bell-shaped stage distribution (mild: 2.9%, moderate: 9%, severe: 5.4%, very-severe: 2.7%). Approximately 73% of patients were stratified as moderate (45.4%) or severe (27.3%) by ALAT guidelines, whereas using GOLD-2013 criteria the majority of subjects (approximately 69%) were in group A (46.3%) or group B (22.7%). BODE index score increased as COPD worsened according to ALAT stratification. This is not observed with GOLD2013 criteria (similar values for B and C groups).
  
  
  CONCLUSIONS
  Disease stages differ under ALAT and GOLD-2013 criteria. ALAT identified a greater proportion of COPD subjects in the moderate and severe categories compared with GOLD-2013, where the majority were categorised in group A. Future evaluation of the ALAT classification should address its predictive ability in terms of hospitalizations and mortality.
authors.affiliation: Servicio de Neumología, Hospital Universitario de Caracas, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela. Electronic address: montesdeoca.maria@gmail.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Montes de Oca
authors.affiliation: Universidad de la República, Facultad de Medicina, Hospital Maciel, Montevideo, Uruguay.
authors.forename: María Victorina
authors.initials: MV
authors.lastname: López Varela
authors.affiliation: Servicio de Neumología, Hospital Universitario de Caracas, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Laucho-Contreras
authors.affiliation: Fundación Neumológica Colombiana, Bogotá, Colombia.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Casas
authors.affiliation: Hospital de Rehabilitación Respiratoria María Ferrer, Buenos Aires, Argentina.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Schiavi
authors.affiliation: Universidad de la República, Facultad de Medicina, Hospital Maciel, Montevideo, Uruguay.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Rey
authors.affiliation: AstraZeneca Medical Affairs, Caracas, Venezuela.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Silva
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification* / Q000175:diagnosis*; D012720:Severity of Illness Index
keywords: Asociación Latinoamericana de Tórax; Atención primaria; Chronic obstructive pulmonary disease; Enfermedad pulmonar obstructiva crónica; Global initiative for chronic obstructive lung disease; Latin American Thoracic Association; Primary care