Is outdoor air pollution associated with physician visits for allergic rhinitis among the elderly in Toronto, Canada?

• Published in: Allergy (Copenhagen) 2006-06, Vol.61 (6), p.750-758
• Main Authors: Villeneuve, P. J., Doiron, M.‐S., Stieb, D., Dales, R., Burnett, R. T., Dugandzic, R.
• Format: Article
• Language: English
• Subjects: Aged; Air Pollutants - adverse effects; air pollution; Allergic diseases; allergic rhinitis; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Fundamental immunology; hay fever; Humans; Immunopathology; Medical sciences; Ontario; Physicians - utilization; Rhinitis, Allergic, Perennial - physiopathology; Rhinitis, Allergic, Perennial - therapy; Rhinitis, Allergic, Seasonal - physiopathology; Rhinitis, Allergic, Seasonal - therapy; Seasons; time series
• ISSN: 0105-4538; 1398-9995
• DOI: 10.1111/j.1398-9995.2006.01070.x

Background:  While a number of studies suggest that air pollution is associated with allergic rhinitis in children, findings among adults have been equivocal. The aim of this study was to examine the relationship between outdoor air pollution and physician visits for allergic rhinitis among individuals ≥65 years of age in Toronto, Canada. Methods:  Physician visits were identified by using data from the Ontario provincial health insurance plan that is made available to all residents. Our analyses are based on 52 691 physician visits for allergic rhinitis among individuals ≥65 years of age in the Toronto metropolitan area between 1995 and 2000. Generalized linear models were used to regress daily counts of physician visits against daily measures of gaseous and particulate components of air pollution after controlling for seasonality, potential confounders (temperature, relative humidity, aeroallergens), overdispersion and serial correlation. Results:  A large number of comparisons were undertaken, with most showing no statistically significant associations between daily levels of air pollution and the number of physician visits for rhinitis. In contrast, an interquartile increase in the 10‐day average of ragweed particles increased the mean number of daily rhinitis consultations by 6.4% (95% CI = 0.7–12.4%). Conclusions:  Our findings suggest that outdoor air pollution is a poor predictor of physician visits for allergic rhinitis among the elderly.