Maximally selected chi2 statistics for k x 2 tables
Related Experiment Video
Updated: Oct 8, 2026

Design and Optimization Strategies of a High-Performance Vented Box
Published on: June 9, 2023
1Department of Statistics, Columbia University, New York, New York 10032, USA. betensky@sdac.harvard.edu
Abstract:
It is common in epidemiologic analyses to summarize continuous outcomes as falling above or below a threshold. With such a dichotomized outcome, the usual chi2 statistics for association or trend can be used to test for equality of proportions across strata of the study population. However, if the threshold is chosen to maximize the test statistic, the nominal chi2 reference distributions are incorrect. In this paper, the asymptotic distributions of maximally selected chi2 statistics for association and for trend for the k x 2 table are derived. The methodology is illustrated with data from an AIDS clinical trial. The results of simulation experiments that assess the accuracy of the asymptotic distributions in moderate sample sizes are also reported.
Related Concept Videos
Finding Critical Values for Chi-Square
Introduction to Test of Independence
The test statistic for a test of independence is similar to that of a goodness-of-fit test:
Chi-square Distribution
Chi-square Analysis
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
Hypothesis Test for Test of Independence
H0: The two variables (factors)...
Determination of Expected Frequency
