This table shows incidence rates (per 100,000) of groups exposed to neither risk factors or to one or two risk factors for lung cancer.What is the expected value of incidence rate X on asbestos exposure group among smokers in additive scale? Incidence Rates of Lung Cancer by Asbestos and Smoking Exposure Status
$$\begin{array}{r}
\text { Smoking status }\quad\
\text { Asbestos exposure }
\begin{array} {|l|l|l|}
\hline& \text { Yes } \quad \quad& \text { No }\quad\quad \
\hline \text { Yes (regular exercise) } & 2.0 & 2.6 \
\hline \text { No (no exercise) } & 4.0 & x\
\hline
\end{array}\end{array}$$
A) 4.0
B) 6.0
C) 8.0
D) 12.0
E) 24.0

Question

This table shows incidence rates (per 100,000) of groups exposed to neither risk factors or to one or two risk factors for lung cancer.What is the expected value of incidence rate X on asbestos exposure group among smokers in additive scale? Incidence Rates of Lung Cancer by Asbestos and Smoking Exposure Status
$$\begin{array}{r}
\text { Smoking status  }\quad\
\text { Asbestos exposure }
\begin{array} {|l|l|l|} 
\hline& \text { Yes } \quad \quad& \text { No }\quad\quad \
\hline \text { Yes (regular exercise) } & 2.0 & 2.6 \
\hline \text { No (no exercise) } & 4.0 & x\
\hline
\end{array}\end{array}$$
A) 4.0
B) 6.0
C) 8.0
D) 12.0
E) 24.0

Quizplus · Accepted Answer

The additive model suggests that the combined effect of two risk factors is the sum of their individual effects. Here, the incidence rate for smokers with no asbestos exposure is 2.6, and for non-smokers with asbestos exposure is 4.0. Therefore, the expected incidence rate for smokers with asbestos exposure is 2.6 + 4.0 - 2.0 = 8.0.

This Table Shows Incidence Rates (Per 100,000) of Groups Exposed