Odds

This function calculates the Risk Ratio and the Odds Ratio (OR) on a 2x2 input matrix. Both ratios are computed with confidence intervals. If confidence interval of OR doesn't encompass the value OR=1, then the function computes the Bayesian Credibility Assessment of the test. If the test is credible, the function calculates the Association Parameter Phi. The association parameter Phi=sqrt(chisquare/N). The routine coumputes the Power and, if necessary, the sample sizes needed to achieve a power=0.80 using a modified asymptotic normal method with continuity correction as described by Hardeo Sahai and Anwer Khurshid in Statistics in Medicine, 1996, Vol. 15, Issue 1: 1-21.