The odds ratio Slide 40 Slide 41 Slide 42 Slide 43 The odds ratio here Interpretation of the odds ratio The rare disease assumption The odds ratio vs the risk ratio Odds ratios in crosssectional and cohort studies Example, wrinkle study Interpreting ORs when the outcome is common Interpreting ORs when the outcome is commonComes can often be summarized by estimating odds ratios or risk ratios If the study outcome is sufficiently rare among exposed and unexposed study subjects, the odds ratio for the exposure–outcome association will closely approximate the risk ratio But if the outcome is common and the risk ratio is not close to 1, the odds ratio will beThese ORs are all relative to TT (lowestrisk genotype) not meaningful to apply to an individual Association of rs on 8q24 with colorectal cancer CC CT TT Calculate the diabetes risk for 4 individuals using their genotype data using odds ratios vs likelihood ratios Note whether the two methods of risk estimation provide
Odds Ratios Basic Concepts
