Response rate

The response rate is the share of people in a study who improved by a set amount, often a 50 percent drop in symptoms.

This term is specific to research interpretation and is defined on AnxietyResearch. Shrinktionary, the network's language layer, doesn't currently carry a canonical entry for it.

Response is a defined threshold, not just any improvement. A common definition is a 50 percent reduction on a symptom scale from where the person started. The response rate is the percentage of the group that crossed that line. It is a different and lower bar than remission.

Response rate is a standard way trials report results. It's easy to picture: out of every 100 people treated, how many improved by a meaningful amount. Comparing the response rate in the treatment group with the response rate in the control group shows what the treatment added.

A trial reports a 55 percent response rate for an SSRI and a 35 percent response rate for placebo. The treatment's added benefit is the 20-point gap, not the full 55 percent.

A response rate on its own can mislead, because some people improve no matter what, as the placebo response rate shows. Always compare the treatment's response rate against the control group's. The gap is the real story. Also check how response was defined, since the threshold can vary.