A family of confidence intervals for the ratio of two binomial proportions.

The power divergence family of statistics introduced by Cressie and Read (1984, Journal of the Royal Statistical Society, Series B 46, 440-464) is used to obtain approximate confidence intervals for the ratio of two proportions. Intervals based on inverting the Pearson, likelihood-ratio, and Freeman-Tukey statistics are included in this family. Small-sample comparisons of the intervals are presented.