ABSTRACT
Relative risk (RR) and 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 the presence of a characteristic in altering risk. 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 nd many similarities between the methods described here and the methods described in the preceding chapter for 2 × 2 tables. RR and OR, when considered alone, do emanate from 2 × 2 tables, and thus similarities are apparent. For this reason, a frequent reference to Chapter 13 is made in this chapter.
