Colds as predictors of the onset and severity of COPD exacerbations.
BACKGROUND
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).


CONCLUSIONS
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.
Department of Medicine, Firestone Institute for Respiratory Health, McMaster University, Hamilton, ON, Canada.
Neil W
NW
Johnston
Early Clinical Development Biometrics.
Marita
M
Olsson
Respiratory, Inflammation & Autoimmunity Unit, Innovative Medicines & Early Development.
Staffan
S
Edsbäcker
Medical Evidence and Observational Research Centre.
Maria
M
Gerhardsson de Verdier
Respiratory, Inflammation & Autoimmunity Translational Medicine Unit, Early Clinical Development, Innovative Medicines & Early Development, AstraZeneca Research and Development, Gothenburg, Molndal, Sweden.
Per
P
Gustafson
Respiratory, Inflammation & Autoimmunity Unit, Innovative Medicines & Early Development.
Christopher
C
McCrae
Regional Virology Laboratory, Belfast HSC Trust, Belfast, UK.
Peter V
PV
Coyle
Department of Medicine, Firestone Institute for Respiratory Health, McMaster University, Hamilton, ON, Canada.
R Andrew
RA
McIvor
D000368:Aged; D000369:Aged, 80 and over; D003139:Common Cold / Q000175:diagnosis / Q000503:physiopathology / Q000821:virology*; D018450:Disease Progression; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology / Q000821:virology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000503:physiopathology / Q000821:virology*; D012307:Risk Factors; D012720:Severity of Illness Index
COPD epidemiology; COPD exacerbations; common cold; respiratory infection; respiratory viruses