Hazard Ratio

A hazard ratio is the chance of an event occurring in the treatment group compared to the chance of that event occurring in the control group during a set period.

A hazard ratio <1 indicates that an event is more likely to occur in the control group. (or the intervention of interest may have a protective effect)

A hazard ratio >1 signifies that an event is more likely to occur in the treatment group.

A ratio close to 1 implies little difference between the 2 groups.