Journal of General Internal Medicine

, Volume 22, Issue 11, pp 1560–1565 | Cite as

Geographic Variation in Chronic Obstructive Pulmonary Disease Exacerbation Rates

Original Article



Exacerbations are important disease events for patients with chronic obstructive pulmonary disease (COPD) as they are relatively frequent, result in significant resource use and can indicate worsening disease. Little is known about variation in COPD exacerbation rates across a health system in various geographic regions.


To compare COPD exacerbation rates by regional service networks called Veterans Integrated Service Network (VISN) in the Veterans Health Administration (VA) system.


Retrospective, observational study.


Patients with a COPD diagnosis from October 1999 to September 2000 with follow-up to September 2002.


Acute exacerbations of COPD during the baseline and follow-up periods.


A total of 198,981 patients were identified. Average exacerbation rate at baseline was 0.503 events per person per year. In the follow-up period, there were 187,686 exacerbations experienced by 87,494 persons (44.0% of cohort). During follow-up, the average adjusted exacerbation rate was 0.589 per person per year and varied from 0.335 (95% CI, 0.328–0.342) in VISN 1 to 0.749 (95% CI, 0.735–0.0.763) in VISN 9. Using the median rate of exacerbation during the baseline period as the referent, 9 VISNs had lower adjusted rate ratios and 12 VISNs had higher adjusted rate ratios in the follow-up period.


Geographic variation in the VA VISN system supports evidence that the medical care system including provider factors, and less so patient factors, affect COPD exacerbations. Understanding the reasons underlying this variation in COPD exacerbation rates may lead to improvements in future care and outcomes.


COPD exacerbation geographic variation outcomes 



This research was supported in part by VA HSR&D IIR 03-307 and an unrestricted research grant from Astra-Zeneca Pharmaceuticals. Dr. Joo received support from a T32 (5T32HS000078-08) training grant while conducting this research. The funding agencies had no role in the design, conduct, or interpretation of the study results. A portion of this work was presented at the American Thoracic Society meeting in San Diego, CA, May 2005, in abstract form. Dr. Lee has received research grants from Astra-Zeneca, Pfizer, and Boehringer-Ingelheim in the past 3 years. Disclaimer: The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs or the United States Government.

Conflict of Interest

None disclosed.


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Copyright information

© Society of General Internal Medicine 2007

Authors and Affiliations

  • Min J. Joo
    • 1
    • 2
    • 4
  • Todd A. Lee
    • 1
    • 2
    • 3
  • Kevin B. Weiss
    • 1
    • 2
    • 3
  1. 1.Center for Management of Complex Chronic CareHines VA HospitalHinesUSA
  2. 2.Institute for Healthcare StudiesNorthwestern University Feinberg School of MedicineChicagoUSA
  3. 3.Division of General Internal Medicine, Department of MedicineNorthwestern University Feinberg School of MedicineChicagoUSA
  4. 4.University of IllinoisChicagoUSA

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