On Defense of the Hazard Ratio

ABSTRACT In this short communication, we describe the recent debate on whether the hazard function should be used for causal inference in time‐to‐event studies and consider three different potential outcomes frameworks (by Rubin, Robins, and Pearl, respectively), as well as use the single‐world intervention graph to show mathematically that the hazard function has causal interpretations under all three frameworks. In addition, we argue that the hazard ratio over time can provide a useful interpretation in practical settings.