Table 1

The four category model: risks and cases for a population of size N.

Category
Risk of being in category
Number of people in category
Number of cases in category

ge (high-risk genotype/high-risk exposure)
Rge
γεN
γε RgeN
go (high-risk genotype/low-risk exposure)
Rgo
γ (1-ε)N
γ (1-ε)RgoN
oe (low-risk genotype/high-risk exposure)
Roe
ε (1-γ)N
ε (1-γ)RoeN
oo (low-risk genotype/low-risk exposure)
Roo
(1-ε) (1-γ)N
(1-ε) (1-γ)RooN

Total

N
rtN

Wallace Theoretical Biology and Medical Modelling 2006 3:35   doi:10.1186/1742-4682-3-35