Table 1

Odds Ratio (OR) for risk of disease in first-degree relatives of an affected person to risks of disease in first-degree relatives of an unaffected person, as a function of the inter-quartile risk ratio (RR) for underlying normally distributed familial causes that are normally distributed, correlated r in first-degree relatives, and for which risk is a logistic function; see text and Hopper & Carlin (1992)

RR r = correlation in first-degree relatives

0.2

0.4

0.6

0.8

1.0

1.5

1.01

1.01

1.02

1.02

1.03

2

1.02

1.03

1.05

1.06

1.08

3

1.04

1.08

1.12

1.16

1.21

5

1.08

1.17

1.27

1.38

1.49

10

1.17

1.37

1.61

1.88

2.20

20

1.30

1.67

2.15

2.76

3.53

100

1.66

2.71

4.29

6.70

10.4

Hopper Epidemiologic Perspectives & Innovations 2011 8:2   doi:10.1186/1742-5573-8-2