In a small pilot study women with cardiovascular disease CVD

In a small pilot study, women with cardiovascular disease (CVD) were contacted and asked whether they had ever used estrogen. Each woman with CVD was matched by age, race, weight, and parity to a woman without disease. The results are shown below:

Pair Number

Women with CHD

Women without CHD

1

Estrogen user

Estrogen non-user

2

Estrogen non-user

Estrogen user

3

Estrogen user

Estrogen user

4

Estrogen user

Estrogen non-user

5

Estrogen user

Estrogen non-user

6

Estrogen user

Estrogen non-user

7

Estrogen non-user

Estrogen non-user

8

Estrogen user

Estrogen non-user

9

Estrogen non-user

Estrogen user

10

Estrogen user

Estrogen user

11

Estrogen user

Estrogen non-user

12

Estrogen non-user

Estrogen non-user

Unmatch the pairs. What is the estimated relative risk of cancer when analyzing this study as an unmatched study design?

a.         0.25

b.         1.43

c.          2.80

d.         4.00

e.         3.00

Pair Number	Women with CHD	Women without CHD
1	Estrogen user	Estrogen non-user
2	Estrogen non-user	Estrogen user
3	Estrogen user	Estrogen user
4	Estrogen user	Estrogen non-user
5	Estrogen user	Estrogen non-user
6	Estrogen user	Estrogen non-user
7	Estrogen non-user	Estrogen non-user
8	Estrogen user	Estrogen non-user
9	Estrogen non-user	Estrogen user
10	Estrogen user	Estrogen user
11	Estrogen user	Estrogen non-user
12	Estrogen non-user	Estrogen non-user

Solution

Estimated relative risk = (8*8)/(4*4) = 4

Hence the correct option is d.

	Woman with CHD	Woman without CHD
Estrogen User	8	4
Estrogen Non User	4	8