In a cancer drug trial, a hazard ratio of 0.667 indicates the treatment group is 67% as likely to progress as the placebo group.

“so um uh at the risk of oversimplifying this a little bit let's talk about the hazard ratio over a given period of time but acknowledging that it's it's real magic is its ability to tell you what's happening at any point in time so um let's just pretend we're talking about a cancer drug trial and um the hazard rates I.E the rates of disease progression were 20 in one group and 30 in another group so the people getting the drug progressed 20 of the time the people not getting the drug they're getting the placebo progressed 30 percent of the time so the hazard ratio is the ratio of 0.2 to 0.3 which is 0.667 so in other words they're um the the treatment group was 67 percent as likely to experience disease progression as the control group”