Table 2.

The incidence rate ratios computed with multivariate analysis by Poisson regression*

Characters	Rate ratio	95% confidence interval for rate ratio
Non-Canadian vs Canadian-born	12.27	7.60 to 19.81
Calendar year for non-Canadian-born children	0.98	0.87 to 1.10
Calendar year for Canadian-born children	0.75	0.60 to 0.95
0 to 4 years vs 10 -15 years for Canadian-born children	3.56	1.57 to 8.09
5 to 9 years vs 10 -15 years for Canadian-born children	1.10	0.40 to 3.04
0 to 4 years vs 10 -15 years for non-Canadian-born children	0.18	0.11 to 0.28
5 to 9 years vs 10 -15 years for non-Canadian-born children	0.17	0.11 to 0.28

*Poisson regression model adjusted for birthplace, age and calendar year, and interactions between birthplace and age, birthplace and calendar year