Hazard ratios are typically calculated using Cox proportional hazards models. This statistical technique models the hazard function, which describes the instant rate at which events occur, given that the subject has survived up to a specific time. The model takes the form: \[ h(t) = h_0(t) \exp(\beta X) \] where \(h(t)\) is the hazard function, \(h_0(t)\) is the baseline hazard, \(\beta\) is the coefficient, and \(X\) is the covariate.
