Reduced COPD Exacerbation Risk Correlates With Improved FEV1: A Meta-Regression Analysis

Alexander D Zider; Xiaoyan Wang; Russell G Buhr; Worawan Sirichana; Igor Z Barjaktarevic; Christopher B Cooper

doi:10.1016/j.chest.2017.04.174

Reduced COPD Exacerbation Risk Correlates With Improved FEV₁: A Meta-Regression Analysis

Chest. 2017 Sep;152(3):494-501. doi: 10.1016/j.chest.2017.04.174. Epub 2017 May 5.

Authors

Alexander D Zider¹, Xiaoyan Wang², Russell G Buhr³, Worawan Sirichana⁴, Igor Z Barjaktarevic¹, Christopher B Cooper⁵

Affiliations

¹ Division of Pulmonary and Critical Care Medicine, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA.
² Division of General Internal Medicine and Health Services Research, Department of Medicine, University of California, Los Angeles, Los Angeles, CA.
³ Division of Pulmonary and Critical Care Medicine, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; Department of Health Policy & Management, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA.
⁴ Division of Pulmonary and Critical Care Medicine, Department of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand.
⁵ Division of Pulmonary and Critical Care Medicine, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA. Electronic address: ccooper@mednet.ucla.edu.

Abstract

Background: The mechanism by which various classes of medication reduce COPD exacerbation risk remains unknown. We hypothesized a correlation between reduced exacerbation risk and improvement in airway patency as measured according to FEV₁.

Methods: By systematic review, COPD trials were identified that reported therapeutic changes in predose FEV₁ (dFEV₁) and occurrence of moderate to severe exacerbations. Using meta-regression analysis, a model was generated with dFEV₁ as the moderator variable and the absolute difference in exacerbation rate (RD), ratio of exacerbation rates (RRs), or hazard ratio (HR) as dependent variables.

Results: The analysis of RD and RR included 119,227 patients, and the HR analysis included 73,475 patients. For every 100-mL change in predose FEV₁, the HR decreased by 21% (95% CI, 17-26; P < .001; R² = 0.85) and the absolute exacerbation rate decreased by 0.06 per patient per year (95% CI, 0.02-0.11; P = .009; R² = 0.05), which corresponded to an RR of 0.86 (95% CI, 0.81-0.91; P < .001; R² = 0.20). The relationship with exacerbation risk remained statistically significant across multiple subgroup analyses.

Conclusions: A significant correlation between increased FEV₁ and lower COPD exacerbation risk suggests that airway patency is an important mechanism responsible for this effect.

Keywords: COPD exacerbations; COPD mechanisms; COPD pharmacology.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Airway Resistance / physiology
Disease Progression
Forced Expiratory Volume / physiology
Humans
Pulmonary Disease, Chronic Obstructive / complications*
Pulmonary Disease, Chronic Obstructive / physiopathology*
Regression Analysis
Risk

Abstract

Publication types

MeSH terms

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