Page 279 - Contributed Paper Session (CPS) - Volume 2

CPS1855 Nobutane H.
1,2, … , + /5 indicates duration that socioeconomic events take effect after
0
people experience them

3. Result
A summary of fitting the proposed model are indicated in the Table 2. As
seen from the table the extended age-environment model provides a better
fit to the data that the age-period-cohort model in terms of Akaike's
Information Criterion (AIC).
Table 2. Summary of fitting the proposed model to the data on Table 1
The youngest age-group who are affected by the environment 40-44 years
The oldest age-group who are affected by the environment 65-69 years
Duration that exposure to the environment take effect 30 years
AIC 3324082.66
Difference of AICs between EAE and APC models 13.16

Figure 11 indicate estimated age effect. From the figure we can conclude
that the risk of breast cancer death does not increase after 55 which is around
the period of menopause.
Age effect The risk of breast
0.1
cancer death does
0.1 not increase after 55
0.0 (menopause)
-0.1
-0.1
Most invasive breast -0.2
cancers are found in
women aged 55 and
older.
Figure 9. Estimates of age effects

Figure 12 indicates the estimated environment effects. From the figure it is
suggested that there exist the effects of westernized food culture, low fertility,
increase of the number of pregnancies over 40 and working women, which are
discussed by Minami, et al. (2004). In addition it is also suggested that the
effects of incorporation of mammography to health check for public, which is
consistent with the conclusion by SAIKA and SOBUE (2009).

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