Biostatistics & Outcomes
Outcome measures translate a trial result into terms you can apply to a patient or a formulary decision. A single 2 × 2 table yields the risk in each group, relative risk, relative and absolute risk reduction, number needed to treat or harm, and the odds ratio all at once, so the relationships between them stay visible instead of being computed in isolation. Hazard ratio, incremental cost-effectiveness ratio, and descriptive statistics cover the remaining measures commonly met in the literature.
2 × 2 table — risk, RR, RRR, ARR, NNT, OR
Enter a single 2 × 2 table and obtain every standard measure of effect at once: risk in each group, relative risk, relative and absolute risk reduction, number needed to treat or harm, and the odds ratio.
Hazard ratio
Calculate a hazard ratio from the hazard rates in the treatment and control groups.
Incremental cost-effectiveness ratio (ICER)
Calculate the additional cost per additional unit of effect when comparing two interventions.
Descriptive statistics
Calculate mean, median, mode, range, and standard deviation from a set of values.
Where to go next
- Practice problems — one worked problem for every calculator, solutions hidden until you open them.
- Reference tables and formula sheet — every constant and conversion factor used here, with citations.
- All 58 calculators — the full index, filterable by category.
Other categories
Also known as
2x2 · contingency · relative risk · RR · RRR · ARR · NNT · NNH · odds ratio · OR · number needed to treat · hazard ratio · HR · survival · cox · time to event · kaplan meier · ICER · cost effectiveness · QALY · pharmacoeconomics · incremental cost · willingness to pay · mean · median · mode · average · standard deviation · range · descriptive statistics · IQR