Table 1.
Age distribution of the population based sample in this study including all control subjects of the NLL interviewed in person.
Figure 1.
Average number of the different kinds of examinations (3 years moving averages) considering all three birth cohorts separately for male and female subjects.
The number of examinations rises continuously over lifetime. This rise with age has become significantly steeper in more recent birth cohorts. (NUK: nuclear medical examinations, CT: computed tomography).
Figure 2.
Distribution of the number of different kinds of examinations considering all three birth cohorts separately for male and female subjects.
The diagrams of the birth cohorts show a similar distribution when compared after an age shift of twenty years in such a way that the same time period is listed below one another. It can be noted that the number is generated mainly by conventional examinations. In the older subjects mass screening examinations are responsible for a considerable proportion of all examinations. Figure 2a: Men. Figure 2b: Women. (NUK: nuclear medical examinations, CT: computed tomography).
Figure 3.
Average red bone marrow dose per age (3 years moving averages) for the different birth cohorts separated by gender.
A drop after an increase accompanied by several peaks and a second rise in later years can be observed in the birth cohorts 1920–1929 and 1940–1949. While the first increase is generated by conventional kinds of examinations, the second rise is caused by technically advanced examinations. (NUK: nuclear medical examinations, CT: computed tomography).
Figure 4.
Red bone marrow dose in association with age, calendar year and gender.
A: Red bone marrow dose per age and gender considering all subjects of the sample (N = 2811) independent of birth year. After a rise of dose in childhood the dose per calendar year shows no significant alteration until old age. B: Red bone marrow dose per calendar year considering all subjects of the sample independent of birth year and just separated by gender. A bimodal distribution of dose with an early rise followed by a drop and a second increase can be noticed. A + B In both graphics the dose were averaged over 10 years for smoothing random peaks.
Figure 5.
Distribution of the red bone marrow dose generated by the different categories of examinations for the three birth cohorts for male and female subjects.
The distribution changed from a predominance of conventional and mass screening examinations to a dose generated mainly by technically advanced examinations like computed tomography and cardiac catheter examinations but also nuclear medicine and contrast medium examinations. The vertical dimension formation reflects similar calendar time. The diagrams of the birth cohorts show a similar distribution when compared at a given calendar time. Figure 5a: Men. Figure 5b: Women. (NUK: nuclear medical examinations, CT: computed tomography).
Table 2.
Red bone marrow dose accumulated until the mentioned age and its proportion of the reference value (total dose of the cohort 1920–1929 at the age of 70).
Figure 6.
Point estimates and 95% confidence limits of the multivariate regression model.
Figure 7.
Annual red bone marrow dose by age and calendar year for the three birth cohorts for A) Men, B) Women) based on the multivariate regression model (Table 3).
Each line represents an age range of ten years, determined by the definition of the respective cohorts. Colours indicate calendar years restricted to 5-years intervals starting with 1925. All lines show an increase of annual dose with ten consecutive birth cohorts. Adjacent lines depict annual doses of the same birth cohorts for later calendar years in five year steps. This allows a comparison between the impact of increasing age and secular trend over calendar years. The increase of annual dose is faster over younger years and levels off later in life. The dynamics are basically similar over the three subsequent birth cohorts. The annual dose however with respect to age has considerably decreased over calendar time.
Table 3.
Linear regression models of the annual red bone marrow dose by sex, age and calendar year for all persons together and the three birth cohorts (CI: confidence interval).