Cochran's Q test EN - pdmoerland/wiki-biostatistiek-bilingual GitHub Wiki
Deze pagina lezen in het Nederlands.
This page was translated from the Dutch-language original using AI and has not been fully reviewed. Where the two differ, the Dutch version takes precedence.
In our study we looked at the presence of a particular type of cell in biopsies taken from different areas of the esophagus. For each patient we took three biopsies (1 from each area). The outcome of the biopsies is dichotomous (presence or absence of the cell type). The outcome was as shown in the table. How do I test whether there is a difference across the three areas?
| area 1 | area 2 | area 3 | |
| Present | 1 | 4 | 12 |
| Absent | 14 | 11 | 3 |
| Total | 15 | 15 | 15 |
For this comparison you can use Cochran's Q test. This tests, in a single test, whether there is a difference across the three paired areas. If a difference is found, you can optionally zoom in on a pairwise comparison between 2 areas using McNemar's test.
You will find the test in two places: 1) via Analyze -> Nonparametric Tests -> Legacy Dialogs -> K Related Samples and 2) via Analyze -> Nonparametric Tests -> Related Samples.
Finished reading? You can go to the Overview of all topics, or to Choosing a test for help picking a suitable test or analysis. Want to learn more about biostatistics? Then follow the AMC e-learning Practical Biostatistics. Did you find something on these pages that isn't correct? Does a link not work? Or would you like to contribute to the wiki? Then get in touch with us.
This biostatistics wiki is an initiative of the former statistics helpdesk of Amsterdam UMC, location AMC. Amsterdam UMC staff can request statistical support via intranet.