Landmark Analysis Explorer

Reset the survival clock at a landmark time to see how conditioning on survival-to-date changes the predicted curve and its eligible population.

landmark analysis
conditional survival
dynamic prediction
survival analysis

Baseline vs. landmark survival prediction

Baseline (from t=0)Landmark (conditional on T > s)

Risk set size over time

Eligibility at the landmark

Total patients

260.000

Eligible at s

223.000

Ineligible (event/censored before s)

37.000

S(s)

0.858

Prediction formula

Symbol	Meaning	Current value
s	Landmark time	1.0 yr
τ	Prediction window	2.0 yr
Estimand	P(T > s + τ \| T > s, H(s))

Conditioning changes the question, not just the curve

The baseline curve answers "survival from the moment of surgery." The landmark curve, reset to 1.0 at s and computed only from patients who survived to s, answers a different and often more relevant question for a patient sitting in front of you at their s-year follow-up: survival conditional on having already made it this far.

Preparing the simulation…