Author:
Yang Hui,Xiang Pingchao,Zhang Erming,Guo Wei’An,Shi Yanwei,Zhang Shuo,Tong Zhaohui
Abstract
Abstract
Background
Exacerbations of chronic obstructive pulmonary disease (COPD) are sporadic, acute worsening of symptoms. Identifying predictors of exacerbation frequency may facilitate medical interventions that reduce exacerbation frequency and severity. The objective of this study was to determine predictors of exacerbation frequency and mortality.
Methods
A total of 227 COPD patients were enrolled in a prospective clinical study between January 2000 and December 2011. Reported exacerbations were recorded for the year preceding enrollment and annually thereafter, and patients were grouped by median annual exacerbation frequency into those experiencing infrequent exacerbations (less than one exacerbation annually) and frequent exacerbations (one or more exacerbation annually). Patients experiencing frequent exacerbations were further divided into those experiencing moderately frequent exacerbations (fewer than two exacerbations per year) and severely frequent exacerbations (two or more exacerbations per year). The rate of clinical relapse and survival was recorded over a 10-year period. The mean of follow-up time was 5.15 years per patient.
Results
For patients experiencing infrequent, moderately frequent, and severely frequent exacerbations, median exacerbations in the year preceding enrollment were 0.0, 0.5, 1.0, respectively, and more frequent exacerbations correlated with lower baseline forced expiratory volume in one second (FEV1) (0.81 L, 0.75 L, and 0.66 L, respectively), higher comorbidity (70.7%, 75.0%, and 89.4%, respectively), and greater NPPV use during hospitalization (16.4%, 35.9% and 51.1%, respectively). FEV1 declined and mortality increased with increasing exacerbation frequency.
Conclusions
Exacerbation frequency can be used to generate discreet patient subpopulations, supporting the hypothesis that multiple COPD phenotypes exist and can be used in patient risk stratification.
Publisher
Springer Science and Business Media LLC
Reference24 articles.
1. World Health Report. Geneva: World Health Organization; Available from URL: 2000 http://www.who.int/whr/2000/en/statistics.htm.
2. GOLD Executive and Science Committees: Global strategy for the diagnosis, management and prevention of chronic obstructive pulmonary disease: GOLD Executive Summary updated 2009. http://www.gold-copd.org
3. Vestbo J, Hurd SS, Agustí AG, Jones PW, Vogelmeier C, Anzueto A, Barnes PJ, Fabbri LM, Martinez FJ, Nishimura M, Stockley RA, Sin DD, Rodriguez-Roisin R: Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med 2013, 187: 347–365. 10.1164/rccm.201204-0596PP
4. Anzueto A: Impact of exacerbations on COPD. Eur Respir Rev 2010, 19: 113–118. 10.1183/09059180.00002610
5. Donaldson GC, Seemungal TA, Bhowmik A, Wedzicha JA: Relationship between exacerbation frequency and lung function decline in chronic obstructive pulmonary disease. Thorax 2002, 57: 847–852. 10.1136/thorax.57.10.847