surrogate endpoint
A measurable outcome that substitutes for a clinically meaningful endpoint and is reasonably likely to predict clinical benefit or harm.
Full Definition
Surrogate endpoints are laboratory measurements, imaging findings, or physical signs that are used in clinical trials as substitutes for clinically meaningful outcomes like mortality or major morbidity. In cardiovascular research, common surrogate endpoints include changes in LDL cholesterol levels, blood pressure reduction, or angiographic measures like late lumen loss. While surrogate endpoints can enable faster trial completion and smaller sample sizes, they must be validated to ensure they reliably predict clinical outcomes. The FDA and other regulatory agencies require evidence that changes in surrogate endpoints correspond to meaningful clinical benefits before approving therapies based primarily on surrogate evidence.
Usage
Usage note: Distinguish clearly from clinical endpoints and explain the rationale for using surrogate measures.
In Context
- "Late lumen loss served as a surrogate endpoint for clinical restenosis in this angiographic substudy." — Endpoint selection rationale
- "The trial used LDL cholesterol reduction as a surrogate endpoint, with clinical outcomes assessed in a separate long-term study." — Study design description