If \code{method = "ratiolog"}, the test described in Barraclough et
al. (1996) is performed. If \code{method = "proportion"}, the version
in Barraclough et al. (1995) is used. If \code{method = "difference"},
If \code{method = "ratiolog"}, the test described in Barraclough et
al. (1996) is performed. If \code{method = "proportion"}, the version
in Barraclough et al. (1995) is used. If \code{method = "difference"},