### 9.2.2 Effect measures for dichotomous outcomes

Introductory text

Box 9.2.a: Calculation of risk ratio (RR), odds ratio (OR) and risk difference (RD) from a 2ยด2 table

9.2.2.1 Risk and odds

9.2.2.2 Measures of relative effect: the risk ratio and odds ratio

9.2.2.3 Warning: OR and RR are not the same

9.2.2.4 Measures of absolute effect: the risk difference

9.2.2.5 What is the event?