To conclude that smoking causes lung cancer, you need to establish that
A) there is a significant relation between smoking and lung cancer.
B) lung cancer always follows smoking and does not appear before smoking.
C) there are no other significant variables that influence both lung disease and cancer.
D) All of these are true.

Question

Quizplus · Accepted Answer

All of these are true. To establish causality between smoking and lung cancer, we need to show a significant association between the two, that the exposure (smoking) precedes the outcome (lung cancer), and that there are no other confounding variables that could explain the relationship. Therefore, options A, B, and C are all essential to establish causality.

To Conclude That Smoking Causes Lung Cancer, You Need to Establish