Stephen J.LurieMD, PhD, Senior EditorJody W.ZylkeMD, Contributing Editor
To the Editor: Asthma is one of the most common chronic diseases in Canada,1 and it has been observed that Canadians with low incomes are at increased risk of asthma.2 Based on data from 17 605 participants in the first cycle of the National Population Health Survey (NPHS) in 1994 through 1995, men and women with low incomes had 1.44- and 1.33-fold increases, respectively, in the prevalence of asthma compared with their counterparts with high incomes; however, there was no significant difference observed between middle- and high-income categories.2 A much larger sample size of the second cycle of NPHS allowed us to further explore whether the prevalence of asthma increases consistently with decreasing income.
Chen Y, Tang M, Krewski D, Dales R. Relationship Between Asthma Prevalence and Income Among Canadians. JAMA. 2001;286(8):919-920. doi:10.1001/jama.286.8.919-JLT0822-7-1