statsmodels.stats.contingency_tables.StratifiedTable.test_null_odds#

StratifiedTable.test_null_odds(correction=False)[source]#

Test that all tables have odds ratio equal to 1

This is the ‘Mantel-Haenszel’ test.

Parameters:
correctionbool, optional

If True, use the continuity correction when calculating the test statistic. As in R’s mantelhaen.test, the correction of 0.5 is applied only if |sum(a - E(a))| >= 0.5, where the sum is over the strata and E(a) is the expected count of the upper left cell under the null hypothesis. Otherwise the statistic is not corrected.

Changed in version 0.15.1: The correction is no longer applied if |sum(a - E(a))| is smaller than 0.5. Previously min(0.5, |sum(a - E(a))|) was subtracted, which changed the statistic and p-value in this case. If the variance is zero, the statistic and p-value are now nan instead of inf and 0 when the correction is used.

Returns:
Bunch

A bunch containing the chi^2 test statistic and p-value.