EU MDR FAQ Clinical Equivalence

The MDR allows a clinical evaluation to rely on clinical data for another device only where equivalence to the device under evaluation can be demonstrated. This is not a shortcut around clinical evaluation: the clinical evaluation still has to be planned, continuously conducted, documented, and supported by a clinical evaluation report.

The equivalence argument has to cover technical, biological, and clinical characteristics. The comparison should identify differences, explain why they are not clinically significant for safety or clinical performance, and point to the underlying data rather than relying on a shared product category or broad similarity claim.

For implantable devices and class III devices, MDR equivalence is more constrained. MDCG 2020-5 explains that clinical investigations are generally expected unless the device is a modification of a device already marketed by the same manufacturer and equivalence is demonstrated under the MDR.

Where a manufacturer of an implantable or class III device claims equivalence to a device from another manufacturer, MDCG 2020-5 identifies the MDR contract requirement: the manufacturer needs full access to the technical documentation on an ongoing basis. The guidance also notes that this means relying on a device certified only under the old directives will not be possible for that route.

Equivalence evidence should remain connected to the clinical evaluation and PMCF plan. MDR Annex XIV treats PMCF as the continuous process that updates the clinical evaluation, confirms safety and performance over the device lifetime, checks the benefit-risk ratio, and detects emerging risks on factual evidence.

Equivalent or similar devices may also matter after market entry, but not as a substitute for data on the device under evaluation. PMCF should identify which equivalent or similar-device data will be monitored, why it is relevant, and how new findings will update the clinical evaluation, risk management, or corrective actions.

Retain a reviewer-ready record showing which device was assessed, which presumed equivalent device was used, what data were available, and why the manufacturer concluded that the MDR equivalence criteria were met. The record should sit with the clinical evaluation report and technical documentation, not in an informal rationale detached from the conformity-assessment file.

The strongest evidence package is a structured equivalence table with device-by-device comparisons, data references, identified differences, scientific justifications, and conclusions on whether any difference is clinically significant.