Which of the following statements about odds ratio is wrong?
In a case-control study, the Odds Ratio is used to analyze a 2x2 table comparing the relationship between an Exposure with Case-Control status.
The null hypothesis for an odds ratio is that the odds ratio is equal to 1.
An odds ratio is a ratio of two odds.
An odds ratio calculated from a case-control study can NEVER be used as an estimate of the relative risk.