PURPOSE: To examine the age, period, and cohort effects on asthma prevalence among Canadian adults from 1994/1995 to 2010/2011.
METHODS: Using data from the National Population Health Survey, 13,616 Canadian adults were followed for 16 years. Age was limited to 18-80 years during follow-up. Modified Poisson regression models with generalized estimating equations were used to estimate age, period, and cohort effects on asthma and active asthma prevalence after accounting for sociodemographic factors. Model-based standardization was performed to estimate standardized rates.
RESULTS: Overall asthma prevalence increased from 5% in 1994/1995 to 11% in 2010/2011; decreasing from 12% for 20-year-olds to 6% for 50-60-year-olds and then increased to 8% for 80-year-olds. Individuals aged 20 years had the steepest increase in prevalence between 1994/1995 and 2010/2011. Active asthma prevalence increased from 5% in 1994/1995 to 8% in 2010/2011; decreasing from 8% for 20-year-olds to 5% for 50-60-year-olds and then increased to 6% for 80-year-olds.
CONCLUSIONS: Our findings suggest the presence of age, period, and cohort effects on prevalence of asthma overall and presence of age and period effects on active asthma prevalence in Canadian adults.
Available at: http://works.bepress.com/tara-mullowney/4/