This is an asymptotic approximation, and will not give a meaningful result if any of the cell counts are very small. If "L" is the sample log odds ratio, an approximate 95% confidence interval for the population log odds ratio is . This can be mapped to to obtain a 95% confidence interval for the odds ratio. If we wish to test the hypothesis that the population odds ratio equals one, the two-sided p-value is , where "P" denotes a probability, and "Z" denotes a standard normal random variable.