Table 3– Association between tuberculosis incidence rates and time since arrival among permanent residents who arrived in Canada in 1986–2002

	Time since arrival yrs^#								≤2 yrs : 3–5 yrs RR (95% CI)
	≤2		3–5		6–10		11–16
	Cases	Rate^¶	Cases	Rate^¶	Cases	Rate^¶	Cases	Rate^¶
Sex
Female	2291	56.6	1227	30.9	908	20.2	225	12.7	1.83 (1.71–1.97)
Male	2666	68.6	1125	29.7	919	21.4	252	14.3	2.31 (2.15–2.48)
Age at arrival yrs
<15	305	17.9	119	7.2	151	8.2	41	5.5	2.50 (2.01–3.11)
15–34	2755	75.0	1381	38.0	944	22.0	220	11.9	1.97 (1.85–2.11)
35–64	1357	59.6	662	30.1	532	22.5	172	20.3	1.98 (1.80–2.18)
>64	540	192.7	190	71.6	200	73.6	44	58.7	2.69 (2.28–3.19)
WHO country group⁺
1 (<15)	178	12.5	63	4.4	43	2.6	20	2.7	2.87 (2.14–3.89)
2 (15–50)	1530	39.0	689	17.7	532	12.0	147	8.5	2.20 (2.01–2.41)
3 (51–100)	1761	111.1	834	57.8	725	46.8	174	28.4	1.92 (1.77–2.09)
4 (>100)	1488	147.5	766	77.7	527	46.8	136	30.6	1.90 (1.74–2.07)
Total	4957	62.5	2352	30.3	1827	20.8	477	13.5	2.06 (1.96–2.17)

RR: incidence rate ratio; WHO: World Health Organization. ^#: maximum number of years between an immigrant’s year of arrival and year of diagnosis; ^¶: per 100,000 person-yrs; ⁺: based on the WHO’s estimated incidence of smear-positive tuberculosis per 100,000 population at mid-study period (3-yr average).