$$H_0: p_0=p_1=\ldots = p_k$$

$$H_1: p_0 \leq p_1 \leq \ldots \leq p_k \text{ with } p_k > p_0 $$

Dose scores

Group sizes

Cases per group

p-value of asymptotic test:

p-value of exact test:

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Brief Description:

This app computes the one-sided p-values of the Cochran-Armitage trend test for the asymptotic and the exact conditional test. The test statistic used for the asymptotic test can e.g. be found in the paper by Portier and Hoel. The exact conditional test has been established by Williams. The computation of its p-value is performed using an algorithm following an idea by Mehta, et al.

Armitage, P. Tests for linear trends in proportions and frequencies.

Cochran, W. G. Some methods for strengthening the common χ ² tests.

Mehta, C. R., Nitin P., and Pralay S. Exact stratified linear rank tests for ordered categorical and binary data.

Portier, C., and Hoel D. Type 1 error of trend tests in proportions and the design of cancer screens.

Williams, D. A. Tests for differences between several small proportions.