A comparison of stratified and adjusted trend tests for binomial proportions.

For the problem of testing for a monotonic trend between an ordinal exposure and a binary response while controlling for categorical cofactors, we derived stratified and adjusted versions of two single contrast tests. Using simulations, we compared their statistical properties to those of the commonly used stratified Mantel-extension trend (MET) test. All tests had high power in case of monotonic relationships between exposure and response. In case of non-monotonic relationships, the stratified and adjusted contrast tests were markedly less powerful than the stratified MET-test particularly for five exposure levels, a favourable feature when the aim is to test for the existence of a monotonic dose-response relationship. These results are illustrated by an example.