ABSTRACT
Relative risk (RR) and the odds ratio (OR) are extensively used in medicine and health for assessing the chance of outcome or antecedent in one group relative to the other. The concepts have been found extremely useful in describing the importance of certain characteristics in altering the outcome. In view of the wide applicability of RR and OR, this chapter is exclusively devoted to these concepts. Statistically, this is an exercise in comparing proportions in two groups. You may find many similarities between the methods described here and the methods described in Chapter 13 for 2×2 tables. RR and OR, when considered alone, do emanate from 2×2 tables, and thus similarities are apparent. For this reason, frequent reference to Chapter 13 is made in this chapter.
