Colds as predictors of the onset and severity of COPD exacerbations

Abstract

Rationale

Common colds are associated with acute respiratory symptom exacerbations in COPD patients.

Objective

To determine exacerbation risk and severity in COPD patients with/without coincident self-reported colds.

Methods

Global initiative for chronic Obstructive Lung Disease stage I–IV COPD patients electronically transmitted respiratory symptom diaries to research staff daily between December 2006 and April 2009. Respiratory symptom worsening prompted contact by a study nurse and patient assessment to determine if a cold was present or an exacerbation underway. A composite daily symptom score was derived for each subject from diarized symptom data. The exacerbation/cold/virus relation was examined using a Poisson regression model, the relation of colds to respiratory symptom severity using generalized estimating equation models.

Results

Daily diary transmission compliance of >97% enabled detection of all possible exacerbations. Among 262 exacerbations meeting Anthonisen criteria, 218 (83%) had cold-like symptoms present at their inception, but respiratory viruses were detected in only 106 (40%). Within-subject exacerbation risk was 30 times (95% confidence interval [CI]: 20, 47; P<0.001) greater with colds present. Compared to cold- and virus-negative exacerbations (n=57), the mean increase in composite symptom score in those cold and virus positive (n=79) was 0.93 (95% CI: 0.61, 1.25; P<0.001), cold-positive and virus-negative exacerbations (n=100) 0.51 (95% CI: 0.21, 0.81; P<0.001), cold-negative and virus-positive exacerbations (n=26) 0.58 (95% CI: 0.23, 0.94; P<0.001).

Conclusion

This study emphasizes the importance of colds in COPD exacerbation risk and severity, even in the absence of virus detection. COPD patients should act promptly when cold symptoms appear to facilitate early intervention for exacerbation prevention or management.

Keywords:

• COPD exacerbations
• respiratory infection
• COPD epidemiology
• respiratory viruses
• common cold

Supplementary materials

Figure S1 Fax daily diary form.

Table S1 BlackBerry daily diary

Acknowledgments

This study was supported by an unrestricted grant from AstraZeneca PLC. Preliminary data from this study were included in an abstract (1105) accepted for the European Respiratory Society 2015 Meeting and presented in a poster at the European Respiratory Society International Congress in Amsterdam, The Netherlands, September 26th to 30th, 2015.³⁰

Author contributions

Mr Johnston is the guarantor of this report, led the study design team, supervised the conduct of the study, and drafted the manuscript. Dr McIvor clinically assessed study patients, led patient recruitment, and co-supervised conduct of the original clinical study. Drs Gerhardsson de Verdier, Gustafson, Edsbacker, and Mr McCrae provided intellectual guidance throughout the study’s inception, design, and conduct. Professor Coyle supervised and interpreted virological testing for the study. Dr Olsson designed and conducted the statistical analyses. All authors contributed toward data analysis, drafting and critically revising the paper, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

Mr Johnston has received research funding and/or honoraria from Merck Canada, Inc., GlaxoSmithKline Canada, and AstraZeneca PLC. Dr McIvor has received honoraria from pharmaceutical companies, including AstraZeneca, Boehringer Ingelheim, Takeda, Pfizer, Merck, and GlaxoSmithKline for educational events, advisory boards, and Phase 3 clinical trials. Authors Gerhardsson de Verdier, Gustafson, McCrae, Edsbäcker, and Olsson are employed by AstraZeneca and own shares in the company. Professor Coyle has received honoraria from pharmaceutical companies (Roche, Randox, and Abbott) for educational events, advisory boards, and is a founding director of the start-up company Hibergene. The authors report no other conflicts of interest in this work.