Skip to main content
. Author manuscript; available in PMC: 2012 Jul 1.
Published in final edited form as: Ann Epidemiol. 2011 May 7;21(7):536–542. doi: 10.1016/j.annepidem.2011.03.001

Figure 3.

Figure 3

Figure 3

Observed ( Inline graphic) and expected [under assumption 11: ( Inline graphic) and under assumption 22(▴) female to male MS incidence by birth cohort.

A. Canada
B. Denmark

Assumptions:

1: In both males and females, the IRR of MS in smokers compared to non-smokers =1.4

2: In females, the IRR of MS in smokers compared to non-smokers =1.6 In males, the IRR of MS in smokers compared to non-smokers = 2.7 [24]

A) Canada:

Under assumption 1 above, rate of change in observed MS: 7.66% per 5 year period; Rate of change in expected MS: 1.58% per 5 year period; Percent of F:M MS ratio potentially explained by smoking: 20.6%

Under assumption 2 above, rate of change in observed MS: 7.66% per 5 year period; Rate of change in expected MS: 6.86% per 5 year period; Percent of F:M MS ratio potentially explained by smoking: 89.6%

B) Denmark:

Under assumption 1 above, rate of change in observed MS: 4.8 % per 5 year period; Rate of change in expected MS: 0.67% per 5 year period; Percent of F:M MS ratio potentially explained by smoking by birth cohort: 14.0%

Under assumption 2 above, rate of change in observed MS: 4.8 % per 5 year period; Rate of change in expected MS: 4.5% per 5 year period; Percent of F:M MS ratio potentially explained by smoking by birth cohort: 94%