COPD phenotypes: differences in survival
Received 21 February 2018
Accepted for publication 26 April 2018
Published 20 July 2018 Volume 2018:13 Pages 2245—2251
Checked for plagiarism Yes
Review by Single-blind
Peer reviewer comments 2
Editor who approved publication: Dr Richard Russell
Julio Hernández Vázquez,1 Ismael Ali García,1 Rodrigo Jiménez-García,2 Alejandro Álvaro Meca,2 Ana López de Andrés,2 Carmen Matesanz Ruiz,1 María Jesús Buendía García,1 Javier de Miguel Díez3
1Respiratory Department, Hospital Universitario Infanta Leonor, Madrid, Spain; 2Preventive Medicine and Public Health Teaching and Research Unit, Health Sciences Faculty, Rey Juan Carlos University, Alcorcón, Madrid, Spain; 3Respiratory Department, Hospital General Universitario Gregorio Marañón, Facultad de Medicina, Universidad Complutense de Madrid (UCM), Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
Background: The aim of the study was to analyze the characteristics and survival of a group of patients with COPD according to their clinical phenotype.
Patients and methods: The study population was selected from patients undergoing scheduled spirometry between January 1, 2011 and June 30, 2011 at the respiratory function laboratory of a teaching hospital and comprised those with a previous and confirmed diagnosis of COPD and forced expiratory volume in the first second (FEV1) of <70%. The patients selected were classified into 4 groups: positive bronchodilator response, non-exacerbator, exacerbator with emphysema, and exacerbator with chronic bronchitis. Patients were followed up until April 2017.
Results: We recruited 273 patients, of whom 89% were men. The distribution by phenotype was as follows: non-exacerbator, 47.2%; positive bronchodilator response, 25.8%; exacerbator with chronic bronchitis, 13.8%; and exacerbator with emphysema, 13.0%. A total of 90 patients died during follow-up (32.9%). Taking patients with a positive bronchodilator response as the reference category, the risk factors that were independently associated with death were older age (HR, 1.06; 95% CI, 1.03–1.09), lower FEV1 (HR, 0.98; 95% CI, 0.96–0.99), and exacerbator with chronic bronchitis phenotype (HR, 3.28; 95% CI, 1.53–7.03).
Conclusion: Classification of COPD patients by phenotype makes it possible to identify subgroups with different prognoses. Thus, mortality was greater in exacerbators with chronic bronchitis and lower in those with a positive bronchodilator response.
Keywords: COPD, phenotypes, positive bronchodilator response, chronic bronchitis, emphysema, exacerbator, mortality
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