Clinical reference standard (CRS)

Diagnostic accuracy is measured against the clinical reference standard, so a weak standard weakens every result. It must be decided without using the output of the device under study.

Best available method for establishing the true status of a subject’s target condition; it can be a single method or combination of methods and techniques including clinical follow-up, but it should not consider the investigational device output.

FDA guidance: Design Considerations for Pivotal Clinical Investigations for Medical Devices (November 2013), Section 11, Glossary