Relative Risk: Epidemiology, Probability, Poisson Regression, Delta Method, Clinical Trial, Estimator, Statistical Inference, Bayesian Convergence of Random Variables

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In statistics and mathematical epidemiology, relative risk (RR) is the risk of an event (or of developing a disease) relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group.[1] RR= frac {p_text{exposed}}{p_text{non-exposed}} Consider an example where the probability of developing lung cancer among smokers was 20% and among non-smokers 1%. This situation is expressed in the 2 × 2 table to the right. Risk Disease status Present Absent Smk a b Non-smk c d Here, a = 20(%), b = 80, c = 1, and d = 99. Then the relative risk of cancer associated with smoking would be RR=frac {a/(a+b)}{c/(c+d)} = frac {20/100}{1/100} = 20. Smokers would be twenty times as likely as non-smokers to develop lung cancer.