DescTools (version 0.99.57)

WoolfTest: Woolf Test For Homogeneity in 2x2xk Tables

Description

Test for homogeneity on \(2 \times 2 \times k\) tables over strata (i.e., whether the log odds ratios are the same in all strata).

Usage

WoolfTest(x)

Value

A list of class "htest" containing the following components:

statistic

the chi-squared test statistic.

parameter

degrees of freedom of the approximate chi-squared distribution of the test statistic.

p.value

\(p\)-value for the test.

method

a character string indicating the type of test performed.

data.name

a character string giving the name(s) of the data.

observed

the observed counts.

expected

the expected counts under the null hypothesis.

Arguments

x

a \(2 \times 2 \times k\) table, where the last dimension refers to the strata.

Author

David Meyer, Achim Zeileis, Kurt Hornik, Michael Friendly

References

Woolf, B. 1955: On estimating the relation between blood group and disease. Ann. Human Genet. (London) 19, 251-253.

See Also

mantelhaen.test, BreslowDayTest

Examples

migraine <- xtabs(freq ~ .,
            cbind(expand.grid(treatment=c("active","placebo"),
                               response=c("better","same"),
                               gender=c("female","male")),
                  freq=c(16,5,11,20,12,7,16,19))
            )

WoolfTest(migraine)