Survival Analysis - Basic Math

Survival function = Probability of surviving beyond time t \(S(t) = P(T > t)\)

Hazard (HAZ) = probability of dying in next few seconds given that you’re alive now \(P(T < (t + \delta) | T > t)\)

Hazard Ratio (HR) = \(\frac{HAZ, x=1}{HAX, x=0}\) - If HR = 2 that means that somebody who is exposed has double the risk of dying than somebody who is not exposed. - Rate of decrease of the Hazard