title: Increased risk of exacerbation and hospitalization in subjects with an overlap phenotype: COPD-asthma.
abstract: BACKGROUND
  Several COPD phenotypes have been described; the COPD-asthma overlap is one of the most recognized. The aim of this study was to evaluate the prevalence of three subgroups (asthma, COPD, and COPD-asthma overlap) in the Latin American Project for the Investigation of Obstructive Lung Disease (PLATINO) study population, to describe their main characteristics, and to determine the association of the COPD-asthma overlap group with exacerbations, hospitalizations, limitations due to physical health, and perception of general health status (GHS).
  
  
  METHODS
  The PLATINO study is a multicenter population-based survey carried out in five Latin American cities. Outcomes were self-reported exacerbations (defined by deterioration of breathing symptoms that affected usual daily activities or caused missed work), hospitalizations due to exacerbations, physical health limitations, and patients' perception of their GHS obtained by questionnaire. Subjects were classified in three specific groups: COPD--a postbronchodilator (post-BD) FEV₁/FVC ratio of < 0.70; asthma--presence of wheezing in the last year and a minimum post-BD increase in FEV₁ or FVC of 12% and 200 mL; and overlap COPD-asthma--the combination of the two.
  
  
  RESULTS
  Out of 5,044 subjects, 767 were classified as having COPD (12%), asthma (1.7%), and COPD-asthma overlap (1.8%). Subjects with COPD-asthma overlap had more respiratory symptoms, had worse lung function, used more respiratory medication, had more hospitalization and exacerbations, and had worse GHS. After adjusting for confounders, the COPD-asthma overlap was associated with higher risks for exacerbations (prevalence ratio [PR], 2.11; 95% CI, 1.08-4.12), hospitalizations (PR, 4.11; 95% CI, 1.45-11.67), and worse GHS (PR, 1.47; 95% CI, 1.18-1.85) compared with those with COPD.
  
  
  CONCLUSIONS
  The coexisting COPD-asthma phenotype is possibly associated with increased disease severity.
authors.affiliation: Postgraduate Program in Epidemiology (Drs Menezes and Wehrmeister), Federal University of Pelotas, Pelotas, Brazil. Electronic address: anamene@terra.com.br.
authors.forename: Ana Maria B
authors.initials: AMB
authors.lastname: Menezes
authors.affiliation: Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: Maria
authors.initials: M
authors.lastname: Montes de Oca
authors.affiliation: Sleep Clinic and Pulmonary Physiology, National Institute of Respiratory Diseases, Mexico City, Mexico.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Pérez-Padilla
authors.affiliation: GlaxoSmithKline, London, England.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Nadeau
authors.affiliation: Postgraduate Program in Epidemiology (Drs Menezes and Wehrmeister), Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Fernando César
authors.initials: FC
authors.lastname: Wehrmeister
authors.affiliation: Facultad de Medicina, Universidad de la Republica, Montevideo, Uruguay.
authors.forename: Maria Victorina
authors.initials: MV
authors.lastname: Lopez-Varela
authors.affiliation: Centro Hospitalario Pereira Rossell, Montevideo, Uruguay.
authors.forename: Adriana
authors.initials: A
authors.lastname: Muiño
authors.affiliation: Federal University of São Paulo, São Paulo, Brazil.
authors.forename: José Roberto B
authors.initials: JRB
authors.lastname: Jardim
authors.affiliation: Pontificia Universidad Católica de Chile, Santiago de Chile, Chile.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Valdivia
authors.affiliation: Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: Carlos
authors.initials: C
authors.lastname: Tálamo
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology* / Q000503:physiopathology; D015897:Comorbidity; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006306:Health Surveys; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007843:Latin America / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010641:Phenotype; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology; D012307:Risk Factors; D012720:Severity of Illness Index; D014797:Vital Capacity / Q000502:physiology