COPD disease severity and the risk of venous thromboembolic events: a matched case–control study
File(s)
Author(s)
Morgan, A
Herrett, E
de Stavola, B
Smeeth, L
Quint, JK
Type
Journal Article
Abstract
Background It is generally accepted that people with chronic obstructive pulmonary disease (COPD) are at increased risk of vascular disease, including venous thromboembolism (VTE). While it is plausible that the risk of arterial and venous thrombotic events is greater still in certain subgroups of COPD patients, such as those with more severe airflow limitation or more frequent exacerbations, these associations, in particular those between venous events and COPD severity or exacerbation frequency, remain largely untested in large population cohorts.
Methods 3,594 COPD patients with a first VTE event recorded during the period 1 January 2004 to 31 December 2013 were identified from the Clinical Practice Research Datalink (CPRD) dataset and matched on age, sex and GP practice (1:3) to COPD patients with no history of VTE (n=10,782). COPD severity was staged by degree of airflow limitation (i.e. GOLD stage) and by COPD medication history. Frequent exacerbators were defined as COPD patients with ≥ 2 exacerbations in the 12-month period prior to their VTE event (for cases) or their selection as a control (for controls). Conditional logistic regression was used to estimate the association between disease severity or exacerbation frequency and VTE.
Results After additional adjustment for non-matching confounders, including BMI, smoking and heart-related comorbidities, there was evidence for an association between increased disease severity and VTE when severity was measured either in terms of lung function impairment (ORmoderate:mild = 1.16; 95% CIs: 1.03, 1.32) or medication usage (ORsevere:mild/moderate = 1.17; 95% CIs: 1.06, 1.26). However, there was no evidence to suggest that frequent exacerbators were at greater risk of VTE compared with infrequent exacerbators (OR = 1.06; 95%: CIs 0.97, 1.15).
Conclusion COPD severity defined by airflow limitation or medication usage but not exacerbation frequency appears to be associated with VTE events in people with COPD. This finding highlights the disconnect between disease activity and severity in COPD.
Methods 3,594 COPD patients with a first VTE event recorded during the period 1 January 2004 to 31 December 2013 were identified from the Clinical Practice Research Datalink (CPRD) dataset and matched on age, sex and GP practice (1:3) to COPD patients with no history of VTE (n=10,782). COPD severity was staged by degree of airflow limitation (i.e. GOLD stage) and by COPD medication history. Frequent exacerbators were defined as COPD patients with ≥ 2 exacerbations in the 12-month period prior to their VTE event (for cases) or their selection as a control (for controls). Conditional logistic regression was used to estimate the association between disease severity or exacerbation frequency and VTE.
Results After additional adjustment for non-matching confounders, including BMI, smoking and heart-related comorbidities, there was evidence for an association between increased disease severity and VTE when severity was measured either in terms of lung function impairment (ORmoderate:mild = 1.16; 95% CIs: 1.03, 1.32) or medication usage (ORsevere:mild/moderate = 1.17; 95% CIs: 1.06, 1.26). However, there was no evidence to suggest that frequent exacerbators were at greater risk of VTE compared with infrequent exacerbators (OR = 1.06; 95%: CIs 0.97, 1.15).
Conclusion COPD severity defined by airflow limitation or medication usage but not exacerbation frequency appears to be associated with VTE events in people with COPD. This finding highlights the disconnect between disease activity and severity in COPD.
Date Issued
2016-04-28
Date Acceptance
2016-02-04
Citation
International Journal of COPD, 2016, 11 (1), pp.899-908
ISSN
1178-2005
Publisher
Dove Medical Press
Start Page
899
End Page
908
Journal / Book Title
International Journal of COPD
Volume
11
Issue
1
Copyright Statement
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for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php).
and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you
hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission
for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php).
License URL
Sponsor
British Lung Foundation
Grant Number
RG14-5
Subjects
Respiratory System
Publication Status
Published