Odds Ratio Interval Calculator
Audit a crude odds ratio and approximate log-Wald interval from four positive independent-group cell counts.
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Calculate a crude independent-group odds ratio and approximate 95% log-Wald interval. All default values are fictional.
Calculation results
Odds ratio (group 1 / group 2): 2.25
95% lower limit: 0.994295
95% upper limit: 5.09155
Log-scale standard error: 0.416667
Assumptions and limits
OR = ad/bc; log-scale SE = sqrt(1/a+1/b+1/c+1/d). All four cells must be positive integers, at most 100 million each. Zero cells are rejected: no silent continuity correction. Sparse-data approximation may be poor even with positive cells. Not for matched pairs, adjusted models or causal interpretation. In a case-control sample, rows must reflect exposure groups and columns outcome status; sampled proportions do not estimate population risks.
Cochrane: effect measures · Read the practical guide · Download blank worksheet (TXT)