Framingham 10year CHD risk estimate*

Estimated prevalence of a CAC score in the given range†, %



0

1–100

101–400

>400


2.5%

75

19

4

1

5.0%

68

23

6

2

7.5%

61

28

8

3

10.0%

52

32

11

5

12.5%

44

36

13

7

15.0%

36

38

17

9

17.5%

29

40

19

12

20.0%

22

41

22

15

22.5%

17

40

25

18

25.0%

13

39

27

22

 * – 10year risk of CHD events estimated according to equations derived from the Framingham study[16]. For assumptions, see Methods.
 † – Proportions of subjects in each given CAC score category were estimated by a two step process: 1) Logistic regression to predict the presence of CAC according to estimated 10year risk (see Table 2 for model coefficients), and 2) Linear regression to predict the extent of CAC, as measured by the natural logtransformed CAC score (see Table 3 for model coefficients). Other values required for this calculation were the logistic regression constant (1.44), the linear regression constant (3.17), and the standard deviation of the residuals after linear regression (1.707).
 CAC – Coronary artery calcium; CHD – Coronary heart disease.