Association of Immigrant Generational Status with Asthma

Objective: We sought to examine whether asthma risk is lower in second-generation immigrants (i.e., Canadian-born children with at least one foreign-born parent) and first-generation immigrants (i.e., foreign-born children) compared with non-immigrants (i.e., Canadian-born children to Canadian-born parents).

Methods: Data were obtained from the Canadian National Longitudinal Survey of Children and Youth from 1994 to 2008, which measured child health and developmental factors from birth to early adulthood. The sample included 15,799 participants aged 2-26 years. Asthma was defined as diagnosis by a health professional as having asthma, having wheezing or whistling in the chest, or use of medication for asthma.

Results: Prevalence of asthma (defined as a combination of any three factors) was lower in first-generation (32%) and second-generation (34%) immigrants compared with non-immigrants (46%). After controlling for covariates, first- and second-generation immigrants had 0.21 (AOR = 0.21; 95% CI = 0.07-0.67) and 0.19 (AOR = 0.19; 95% CI = 0.09-0.39) lower odds of reporting asthma compared with non-immigrants, respectively. For every year the parent(s) of second-generation immigrants resided in Canada, the odds for asthma increased by 5% (AOR = 1.05; 95% CI = 1.02-1.06).

Conclusion: Immigrant children and youth in Canada, regardless of whether they are first- or second-generation, have lower odds for asthma compared with non-immigrants.