Surrogate and Mediating Endpoints: Current Status and Future Directions

Abstract

The identification of surrogate endpoints that can replace “true” endpoints in clinical trials could provide an important advance for the evaluation of therapeutic or preventive interventions. Outcome events that are more frequent in occurrence and more proximate in time, compared with customary disease-specific mortality or incidence outcomes, could give answers that are based on smaller trials of shorter duration. However, reliance on surrogate outcomes is justifiable only if treatment comparisons that are based on a surrogate are a faithful reflection of comparisons that are based on the true endpoint.