Intervention effects: Hazard ratios

Hazard ratios are often used to describe the effect of an intervention when the outcome is a survival outcome (i.e., how long does someone survive before the event happens). In this video I delve a little into proportional hazards and how to test that proportional hazards is a reasonable assumption (a prerequisite for using a hazard ratio in your model) and then show how hazard ratios get used in your model.