# Category Archive: Bioinformatics

Jul

10

## Reverse engineering contingency (2×2) table from Odds Ratio (OR)

Given the odds ratio (OR), we will calculate the individual cells in the contingency table (a,b,c,d). In yellow, I’ve highlighted what is known. a,b,c, and d are unknown and what we want to calculate. Odds Ratio = (a/c) / (b/d) Cases Controls Total Exposed a b total_exposed (a+b) Unexposed c d total_unexposed(c+d) Total total_cases(a+c) total_controls(b+d) …