Does socio-demographic status influence the effect of pollens and molds on hospitalization for asthma? Results from a time-series study in 10 Canadian cities.
OBJECTIVE
Social status influences asthma morbidity but the mechanisms are not well understood. To determine if sociodemographics influence the susceptibility to ambient aeroallergens, we determined the association between daily hospitalizations for asthma and daily concentrations of ambient pollens and molds in 10 large Canadian cities.


METHODS
Daily time-series analyses were performed and results were adjusted for day of the week, temperature, barometric pressure, relative humidity, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Results were then stratified by age, gender, and neighborhood family education and income.


RESULTS
There appeared to be age and gender interactions in the relation between aeroallergens and asthma. An increase in basidiomycetes equivalent to its mean value, about 300/m3, increased asthma admissions for younger males (under 13 years of age) by 9.3% (95% CI, 4.8%, 13.8%) vs. 4.2% (95% CI, - 0.1%, 8.5%) for older males. The reverse was true among females with increased effect in the older age group: 2.3% (95% CI, 1.2%, 5.8%) in those under 13 years vs. 7.1% (95% CI, 4.1%, 10.1%) for older females. Associations were seen between aeroallergens and asthma hospitalization in the lowest but not the highest education group.


CONCLUSIONS
Our results suggest that younger males and those within less educated families may be more vulnerable to aeroallergens as reflected by hospitalization for asthma.
Cakmak
Sabit
S
Department of Biostatistics and Epidemiology, Health Canada, Canada.
Dales
Robert E
RE
Judek
Stan
S
Coates
Frances
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D000485:Allergens / Q000633:toxicity*; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology; D001274:Atmospheric Pressure; D001487:Basidiomycota / Q000472:pathogenicity; D002170:Canada / Q000453:epidemiology; D002248:Carbon Monoxide / Q000633:toxicity; D004522:Educational Status; D005260:Female; D005658:Fungi / Q000472:pathogenicity*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000633:toxicity; D010126:Ozone / Q000633:toxicity; D011058:Pollen / Q000633:toxicity*; D012111:Residence Characteristics / Q000145:classification; D012307:Risk Factors; D012923:Social Class; D012959:Socioeconomic Factors; D016008:Statistical Distributions; D013997:Time Factors; D014887:Weather
D000393:Air Pollutants; D000485:Allergens; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide