Back to Journals » International Journal of Chronic Obstructive Pulmonary Disease » Volume 6

Adjusting for COPD severity in database research: developing and validating an algorithm

Authors Goossens LMA, Baker CL, Monz BU, Zou KH, Rutten-van Mölken MPMH

Published 6 December 2011 Volume 2011:6 Pages 669—678

DOI https://doi.org/10.2147/COPD.S26214

Review by Single-blind

Peer reviewer comments 2

Lucas MA Goossens1, Christine L Baker2, Brigitta U Monz3, Kelly H Zou2, Maureen PMH Rutten-van Mölken1
1Institute for Medical Technology Assessment, Erasmus University, Rotterdam, The Netherlands; 2Pfizer Inc, New York City, NY, USA; 3Boehringer Ingelheim International GmbH, Ingelheim am Rhein, Germany

Purpose: When comparing chronic obstructive lung disease (COPD) interventions in database research, it is important to adjust for severity. Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines grade severity according to lung function. Most databases lack data on lung function. Previous database research has approximated COPD severity using demographics and healthcare utilization. This study aims to derive an algorithm for COPD severity using baseline data from a large respiratory trial (UPLIFT).
Methods: Partial proportional odds logit models were developed for probabilities of being in GOLD stages II, III and IV. Concordance between predicted and observed stage was assessed using kappa-statistics. Models were estimated in a random selection of 2/3 of patients and validated in the remainder. The analysis was repeated in a subsample with a balanced distribution across severity stages. Univariate associations of COPD severity with the covariates were tested as well.
Results: More severe COPD was associated with being male and younger, having quit smoking, lower BMI, osteoporosis, hospitalizations, using certain medications, and oxygen. After adjusting for these variables, co-morbidities, previous healthcare resource use (eg, emergency room, hospitalizations) and inhaled corticosteroids, xanthines, or mucolytics were no longer independently associated with COPD severity, although they were in univariate tests. The concordance was poor (kappa = 0.151) and only slightly better in the balanced sample (kappa = 0.215).
Conclusion: COPD severity cannot be reliably predicted from demographics and healthcare use. This limitation should be considered when interpreting findings from database studies, and additional research should explore other methods to account for COPD severity.

Keywords: GOLD, healthcare resource use, partial proportional odds logit

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. 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.

Download Article [PDF]  View Full Text [HTML][Machine readable]

 

Readers of this article also read:

Physical inactivity and arterial stiffness in COPD

Sievi NA, Franzen D, Kohler M, Clarenbach CF

International Journal of Chronic Obstructive Pulmonary Disease 2015, 10:1891-1897

Published Date: 10 September 2015

How do COPD comorbidities affect ICU outcomes?

Ongel EA, Karakurt Z, Salturk C, Takir HB, Burunsuzoglu B, Kargin F, Ekinci GH, Mocin O, Gungor G, Adiguzel N, Yilmaz A

International Journal of Chronic Obstructive Pulmonary Disease 2014, 9:1187-1196

Published Date: 17 October 2014

Central airways remodeling in COPD patients

Pini L, Pinelli V, Modina D, Bezzi M, Tiberio L, Tantucci C

International Journal of Chronic Obstructive Pulmonary Disease 2014, 9:927-933

Published Date: 1 September 2014

Adjunctive treatment with oral AKL1, a botanical nutraceutical, in chronic obstructive pulmonary disease

Brockwell C, Ampikaipakan S, Sexton DW, Price D, Freeman D, Thomas M, Ali M, Wilson AM

International Journal of Chronic Obstructive Pulmonary Disease 2014, 9:715-721

Published Date: 9 July 2014

P-wave indices in patients with pulmonary emphysema: do P-terminal force and interatrial block have confounding effects?

Chhabra L, Chaubey VK, Kothagundla C, Bajaj R, Kaul S, Spodick DH

International Journal of Chronic Obstructive Pulmonary Disease 2013, 8:245-250

Published Date: 14 May 2013