Risk & Odds Analysis

Compare the likelihood of events between two different groups.

Contingency Data

Exposed / Test Group

ROW A

Event (a)

No Event (b)

Control / Baseline

ROW B

Event (c)

No Event (d)

Effect Size Analysis

Relative Risk (RR)2.000100.0% more likely

Odds Ratio (OR)2.250Cross-product ratio

Effect TypeIncreased

Risk (Exposed)20.0%

Risk (Control)10.0%

Total Sample Size

N = 200

Overview

Relative Risk (RR) and Odds Ratio (OR) are measures of association used in epidemiology and clinical research. RR compares the probability of an event occurring in an exposed group to a control group, while OR compares the odds of an event occurring.

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Pro Tips

Relative Risk is often easier for patients and clinicians to intuitively understand.
Odds Ratio is mathematically symmetric, meaning you get the same result if you swap event/no-event and exposed/control correctly.
Always consider the Absolute Risk Reduction (ARR) to get the full picture of clinical significance.

Calculation Formulas

Relative Risk

RR = [a/(a+b)] / [c/(c+d)]

Odds Ratio

OR = (a*d) / (b*c)

Used with this

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Adjusted Rsquared