Editing Openai/695f02d3-11f8-800e-993a-ad71db6d42aa (section)

==== ✅ HR is a ratio of instantaneous event rates, not a ratio of survival probabilities at a fixed timepoint. Wikipedia<ref>{{cite web|title=Wikipedia|url=https://en.wikipedia.org/wiki/Hazard_ratio|publisher=en.wikipedia.org|access-date=2026-01-10}}</ref> ====
✅ It’s estimated via a regression model (Cox model), usually by exponentiating the treatment coefficient β\betaβ. Easy Made Stat<ref>{{cite web|title=Easy Made Stat|url=https://help.easymedstat.com/support/solutions/articles/77000513111-how-to-calculate-hazard-ratios-hr-in-a-cox-model-|publisher=Easy Made Stat|access-date=2026-01-10}}</ref>
✅ HR < 1 indicates benefit for the treatment over control. Statistical Aid: A School of Statistics<ref>{{cite web|title=Statistical Aid: A School of Statistics|url=https://www.statisticalaid.com/hazard-ratio/|publisher=Statistical Aid: A School of Statistics|access-date=2026-01-10}}</ref>

If you want, I can walk you through a numerical example — e.g., how the Cox model estimates β from a small dataset and turns that into an HR. Just let me know!