Equivalence claims in clinical evaluation
MDR Art. 61(4)–(5) and Annex XIV §3. Equivalence is a tool for leveraging existing clinical data from a comparable device in lieu of a new clinical investigation. Its use is significantly more restricted under MDR than under the previous MDD.
This site provides general information only and does not constitute legal or regulatory advice. Always consult the official regulation text and a qualified regulatory professional.
What is an equivalence claim?
A manufacturer who lacks sufficient clinical data from their own device may use clinical data from an equivalent device to support the clinical evaluation. The equivalent device is one for which sufficient clinical evidence already exists, and which is sufficiently similar to the device under evaluation in all clinically relevant respects.
Equivalence is a tool for accessing clinical data — it does not reduce or eliminate the clinical evaluation requirement. The manufacturer must still conduct a rigorous clinical evaluation; they are simply using data from an equivalent device as a significant data source.
The three equivalence criteria — all must be met
MDR Annex XIV §3 requires that all three of the following criteria are simultaneously met:
1. Clinical equivalence
The devices must:
- Be intended for the same clinical condition or purpose (including similar severity and stage of disease)
- Target the same intended user population (age range, gender, co-morbidities)
- Be used at the same body site (anatomical location, tissue type)
- Achieve similar outcomes in clinical use
Clinical equivalence is the most outcome-focused criterion — is the device going to be used in the same way for the same patients in the same clinical context?
2. Technical equivalence
The devices must:
- Use the same technology or operational principle
- Have similar design specifications (dimensions, material properties, deployment mechanism)
- Use the same materials in patient contact (or materials with documented similar biological safety profiles)
- Have similar software or algorithms where relevant
- Have similar energy delivery parameters (for active devices)
Technical equivalence does not require identical specifications but requires the differences to be characterised and their impact on clinical performance assessed and justified.
3. Biological equivalence
The devices must:
- Use the same materials or have documented equivalent biological safety profiles where materials differ
- Have the same duration of contact with the body (transient, short-term, long-term/permanent)
- Have the same route of contact (surface contact, implanted, mucosal, etc.)
- Have the same absorption, distribution, and degradation characteristics where relevant
Access to the equivalent device's technical documentation
This is the most practically significant change from MDD. Under MDR Art. 61(5):
Where the manufacturer claims equivalence to a device that is not their own device, they must have sufficient access to the technical documentation of the equivalent device on a continuous basis.
For devices from a different manufacturer, this means a formal contractual arrangement granting access. The arrangement must:
- Be in writing
- Allow the manufacturer to review the equivalent device's technical documentation
- Be maintained for the lifetime of the equivalence claim
Publicly available literature about a competitor's device is not sufficient to establish access to technical documentation. Manufacturers who cannot secure a contractual arrangement cannot rely on a competitor's device for equivalence.
For devices from the same manufacturer (e.g. a new generation of the manufacturer's own legacy device), access to technical documentation is inherent — no formal contractual arrangement is needed, but the documentation must exist and be retrievable.
Equivalence for Class III and implantable Class IIb devices
For Class III devices and implantable Class IIb devices, equivalence to a device manufactured by a different company is only permitted in exceptional, justified circumstances. Even where technically meeting all three criteria, the expectation under MDR is that these devices will have their own clinical investigation data.
MDCG 2020-5 states that for Class III devices without an equivalent from the same manufacturer with an established clinical record, a clinical investigation is expected.
Characterising differences between devices
Even where equivalence is established, differences between the device and the equivalent must be characterised:
- What are the specific differences (material, dimensions, software)?
- Could any of these differences affect clinical performance or safety?
- Is there a scientific rationale explaining why the differences do not affect the outcome?
This characterisation must be documented in the CER. If differences exist that could affect clinical outcomes, equivalence cannot be relied upon for those specific claims.
Equivalence vs. general literature
Equivalence is distinct from general literature review:
| Type of evidence | What it supports |
|---|---|
| Clinical data from the device itself | Direct evidence — strongest |
| Clinical data from an equivalent device (with access to tech doc) | Indirect evidence — valid under MDR if criteria met |
| General literature on the device type or clinical area | Context and supporting evidence — not a substitute for device-specific data |
General literature (e.g. on the disease background, standard of care, or clinical outcomes for the device class) provides context but does not constitute equivalence data.
Documenting the equivalence claim in the CER
The CER must include:
- Identification of the equivalent device: manufacturer, device name, model, regulatory status
- Assessment against all three criteria: clinical, technical, and biological — with evidence for each
- Access to technical documentation: confirmation of access (or contractual arrangement)
- Characterisation of differences: documented differences and justification that they do not affect safety/performance
- Conclusion: whether full equivalence is established for each claim being supported
Related pages
- Clinical evaluation overview
- Clinical Evaluation Report (CER)
- Clinical investigations
- Using international clinical data
Official references
| Reference | Description |
|---|---|
| MDR Art. 61(4)–(5) | Equivalence requirements |
| MDR Annex XIV §3 | Equivalence criteria |
| MDCG 2020-5 | Clinical evaluation guidance including equivalence |
| MDCG 2021-6 | Sufficient clinical evidence for legacy devices |
The section should be completed with: 'For Class III devices and implantable Class IIb devices, the use of equivalence is heavily restricted. MDR Art. 61(4) mandates that a clinical investigation must be performed unless the device is a modification of an already-marketed device and the notified body agrees that sufficient clinical evidence exists. Even where equivalence is claimed, the reliance on literature alone is insufficient for these higher-risk devices — post-market clinical follow-up (PMCF) must be planned and justified.'