## What is the null hypothesis for Mantel-Haenszel test?

Technically, the null hypothesis of the Cochran–Mantel–Haenszel test is that the odds ratios within each repetition are equal to 1. The odds ratio is equal to 1 when the proportions are the same, and the odds ratio is different from 1 when the proportions are different from each other.

## What is the Cochran Mantel Haenszel method?

The Cochran-Mantel-Haenszel method is a technique that generates an estimate of an association between an exposure and an outcome after adjusting for or taking into account confounding. The method is used with a dichotomous outcome variable and a dichotomous risk factor.

**Which is the null hypothesis of the Cochran Mantel Haenszel test?**

Null hypothesis. Technically, the null hypothesis of the Cochran–Mantel–Haenszel test is that the odds ratios within each repetition are equal to 1. The odds ratio is equal to 1 when the proportions are the same, and the odds ratio is different from 1 when the proportions are different from each other.

**Which is the correct statistic for the Cochran Haenszel test?**

The Cochran-Mantel-Haenszel (CMH) test statistic is [Pk(n11k−µ11k)]2 = 2 M P kVar(n11k)

### Which is the null hypothesis of conditional independence?

Recall, the null hypothesis of conditional independence is equivalent to the statement that all conditional odds ratios given the levels k are equal to 1, e.g., The Cochran-Mantel-Haenszel ( CMH) test statistic is

### Why does the χ 2mh get bigger on the Haenszel test?

You subtract the 0.5 as a continuity correction. The denominator contains an estimate of the variance of the squared differences. The test statistic, χ 2MH, gets bigger as the differences between the observed and expected values get larger, or as the variance gets smaller (primarily due to the sample size getting bigger).