Impact of influenza infection on the short- and long-term health of patients with chronic obstructive pulmonary disease

Abstract

Background

Influenza is a common cause of acute respiratory infection that leads to exacerbation of underlying chronic obstructive pulmonary disease (COPD). To elucidate the short- and long-term effects of influenza in patients with COPD, we examined health care resource utilization (HRU) and costs up to 13 months following influenza infection.

Methods

We conducted a retrospective cohort study using U.S. insurance claims data from MarketScan. Patients with an influenza diagnosis during the 2012–2014 influenza seasons and continuous enrollment in a health plan from 12 months before to 13 months after the index influenza diagnosis were identified and propensity score–matched 1:5 to controls without evidence of influenza. COPD- and pneumonia-related outcomes were assessed over 13 months following influenza diagnosis.

Results

COPD-associated outcomes after diagnosis were significantly worse in patients with influenza (n = 7,087) vs. controls (n = 35,435) during the first month (exacerbation: 16.1 vs. 3.4%; outpatient visits: 57.1 vs. 35.2%; emergency department (ED) visits: 10.5 vs. 1.8%; and inpatient visits: 5.6 vs. 0.7%) and months 2–13 (exacerbation: 25.1 vs. 21.1%; outpatient visits: 86.1 vs. 85.8%; ED visits: 20.0 vs. 15.7%; and inpatient visits: 6.5 vs. 5.3%). COPD- and pneumonia-associated costs for months 1 and 2–13 were higher in patients with influenza.

Limitations

The study was subject to a residual imbalance between cohorts despite propensity score matching. The use of diagnostic codes to select patients and identify complications could introduce inaccuracies in estimating events.

Conclusions

HRU and costs were higher in COPD patients with influenza during the first month and over the entire year following infection. This suggests influenza has an impact on respiratory health in patients with COPD that lasts beyond the acute infection.

Keywords:

• Chronic obstructive pulmonary disease
• COPD
• influenza
• health care resource utilization
• costs
• long-term
• claims database

JEL CLASSIFICATION CODES:

• I12
• I1
• I
• I10

Transparency

Declaration of funding

The study was sponsored and funded by Genentech, Inc., South San Francisco, CA, USA.

Declaration of financial/other relationships

CW, TMT, SK, HM, and DW are current employees of Genentech/Roche, Inc., and hold Roche stock.

Author contributions

All authors were involved with all aspects of the manuscript–data collection and analysis and manuscript review and approval.

Acknowledgements

Meher M. Dustoor, and Esther Tazartes, of Global Outcomes Group, provided editorial assistance; these services were funded by Genentech, Inc.

Data availability statement

The data that support the findings of this study are available from IBM MarketScan Research Databases, but these data are not publicly available. All relevant data are provided within the manuscript and supporting files.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Previous presentations

This study was presented in poster format at the 6th International Society for Influenza and Other Respiratory Viruses conference, Rockville, MD, 13–15 November 2018.