When researchers measure a combination of possible clinical events in a clinical trial, they have created a composite endpoint. Composite endpoints increase the statistical power of studies, which allows scientists to run smaller, quicker and usually less expensive trials.
Deeper dive
Composite endpoints can be useful when they measure events that are generally of equal severity and importance to patients, such as heart attacks and strokes. But composite endpoints can be misleading if they include surrogate endpoints, especially if those surrogates are more common and less significant than the other outcomes, i.e., a composite endpoint that includes heart attacks, strokes and cholesterol counts. In such muddled composites, the less significant events often drive the supposed effect of the intervention that’s being tested, and they can make a treatment look more effective than it actually is.