Surrogate outcomes (DOEs)
A surrogate outcome is a laboratory measurement or a physical sign used as a substitute for a clinically meaningful outcome.
Some examples of surrogate outcomes include:
- Reduction in cholesterol levels with lipid lowering drugs
- Improvement in XRay appearance following knee surgery
- Reduction in anti-depressant use following counseling for depression
The effect of an intervention on a surrogate outcome should predict the effect on the desired clinical outcome. However, the surrogate outcome may be of little interest to the patient. What they want to know is "will I feel better" or "will I live longer"?