Changes

'''Hazard ratio''' ("HR") is a quantity often used in medical studies to show an a decrease in risk of mortality or harm from using the studied course of treatment.  A hazard ratio of 1 signifies no change, while a hazard ratio of 0.5 signifies a 50% reduction in harm.

'''Hazard ratio''' ("HR") is a quantity often used in medical studies to show a decrease in risk of mortality or harm from using the studied course of treatment.  A hazard ratio of 1 signifies no change, while a hazard ratio of 0.5 signifies a 50% reduction in harm.

In other words, the hazard ratio is the risk of the hazard relative to a control group risk of 1.

In other words, the hazard ratio is the risk of a hazard relative to a control group risk of 1.

The hazard ratio is defined formally in two different ways:<ref>https://www.sciencedirect.com/topics/medicine-and-dentistry/hazard-ratio#:~:text=The%20hazard%20ratio%20is%20the,interval%20of%20time%20(21).</ref>

The hazard ratio is defined formally in two different ways:<ref>https://www.sciencedirect.com/topics/medicine-and-dentistry/hazard-ratio#:~:text=The%20hazard%20ratio%20is%20the,interval%20of%20time%20(21).</ref>