Translate relative effects into absolute risk.

Method and limitations

Fixed-time absolute effects, not treatment recommendations.

Effect Translator applies the selected measure to a stated comparator risk at the same time horizon. It reports a model-based scenario; results depend on the supplied estimate, baseline risk and assumptions.

Hazard ratio boundary

HR translation uses S1(t) = S0(t)^HR only for a compatible fixed-time, proportional-hazards, time-to-first-event context. HR is not a risk ratio.

Cause-specific or subdistribution competing-risk HRs, recurrent-event HRs, time-varying HRs, non-proportional hazards and RMST are unsupported.

Use with care

Check effect definition, outcome horizon, population and baseline-risk relevance before using a translation. This tool does not replace protocol, statistical or clinical review.

References

1. Cochrane Handbook, Chapter 15: Interpreting results and drawing conclusions. Sections 15.4.4.1–15.4.4.5 support baseline-risk-dependent conversion of RR and OR to absolute effects, risk differences, NNT and confidence limits.
2. Altman DG, Andersen PK. Calculating the number needed to treat for trials where the outcome is time to an event. BMJ. 1999;319:1492–1495. Supports time-specific absolute differences and NNT for survival outcomes.
3. Cox DR. Regression Models and Life-Tables. Journal of the Royal Statistical Society: Series B. 1972;34:187–220. Defines the proportional-hazards model underlying the fixed-time survival transformation.
4. Hernán MA. The Hazards of Hazard Ratios. Epidemiology. 2010;21(1):13–15. Explains why a hazard ratio is not a risk ratio and why absolute survival or cumulative-risk measures remain necessary.