statsmodels.stats.contingency_tables.StratifiedTable.test_equal_odds#
- StratifiedTable.test_equal_odds(adjust=False)[source]#
Test that all odds ratios are identical
This is the ‘Breslow-Day’ testing procedure.
- Parameters:
- adjustbool,
optional Use the ‘Tarone’ adjustment to achieve the chi^2 asymptotic distribution.
- adjustbool,
- Returns:
BunchA bunch with attributes
- statisticfloat
The chi^2 test statistic.
- pvaluefloat
The p-value for the test.
Notes
The statistic is computed from the fitted cell counts of each stratum given the pooled (Mantel-Haenszel) odds ratio.
If a stratum has a row or column total of zero, the statistic and the p-value are NaN.
Changed in version 0.15.1: The test can be computed if the pooled odds ratio is exactly 1, where it was NaN before. The fitted counts are computed in a way that avoids a loss of precision if the pooled odds ratio is close to 1 or some fitted counts are small. Results can differ from those of earlier versions by a relative amount of about 1e-12, and by more for tables where the earlier calculation lost precision.