Describing the device and any equivalent you rely on
A clinical evaluation report describes the device under evaluation in enough detail for its compliance to be assessed, from its classification to its usability. A report that relies on equivalence to another device gives full details of that device too, and the two devices have to be equivalent clinically, technically and biologically at once.
The device description
A device's classification is determined with MEDDEV 2.4/1 revision 9, whose rules place a device in class I, IIa, IIb or III by risk, and which in 2017 was to be superseded by MDR Annex VIII.
The device should be described in enough detail for its compliance with the Essential Requirements to be assessed, and the description should always include photographs and diagrams. The section on the device under evaluation must state whether the device is new to the market. MEDDEV 2.7/1 revision 4 lists the information the description includes:
- the name, models, sizes and components of the device, including software and accessories
- the device group it belongs to
- whether the device is in development, undergoing initial CE marking or already CE-marked
- whether the device is on the market in Europe or in other countries, since when, and how many devices have been placed on the market
- the intended purpose: the exact medical indications, where applicable; the disease or condition, its clinical form, stage and severity, and the symptoms or aspects to be treated, managed or diagnosed; the patient populations; the intended user, whether a health professional or a lay person; the organs, tissues or body fluids the device contacts; the duration of use or contact with the body; repeat applications, with any restriction on their number or duration; contact with mucosal membranes, invasiveness or implantation; contraindications; the precautions the manufacturer requires; and whether the device is single use or reusable
- a general description: a concise physical and chemical description, the technical specifications and mechanical characteristics, sterility and radioactivity
Most of this information is found in the instructions for use, and depending on the device a surgical guide may hold more. The intended purpose should use the same wording as the instructions for use, because the instructions for use are part of the Essential Requirements of the Medical Device Directive.
Usability testing of the device is a requirement new in revision 4 of MEDDEV 2.7/1, introduced because usability factors have caused or contributed to many incidents. It means demonstrating that the device design and the risks of its use have been minimised, that the residual risks are acceptable, and that the information materials, such as the instructions for use and the training guide, are suitable for the intended users.
Clinical, technical and biological equivalence
A device marketed on the basis of equivalence to another must be shown to be equivalent clinically, technically and biologically, and all three must be fulfilled. The report should give full details of the equivalent device and the reasons it is considered equivalent.
Clinically equivalent devices are used for the same clinical condition, including similar severity and stage of disease, for the same medical indication and intended purpose, at the same site in the body and in a similar population by age, gender, anatomy and physiology, and they are not foreseen to deliver significantly different performances in the relevant critical performances, such as the expected clinical effect, the specific intended purpose and the duration of use. Technically equivalent devices are of similar design, used under the same conditions of use, with similar specifications and properties, such as the type and intensity of energy, tensile strength, viscosity, surface characteristics, wavelength, surface texture, porosity, particle size, nanotechnology, specific mass and atomic inclusions, with similar deployment methods where relevant, and with similar principles of operation and critical performance requirements. Biologically equivalent devices use the same materials or substances in contact with the same human tissues or body fluids.
Equivalence under revision 4 and the MDR
Revision 4 and the MDR made equivalence much more difficult to claim: besides the strict criteria for clinical, technical and biological equivalence, access to the equivalent device's technical file and a contract with its manufacturer are now also required, for class III devices in particular. Since revision 4, the equivalence approach, which uses data from similar devices rather than from the device in question, has become more challenging, because access to the equivalent device's technical documentation is now indirectly expected, and such access is usually not possible for a competitor's device. The new regulations make claiming equivalence to a competitor's device nearly impossible, because they require a complete data disclosure agreement between the two competitors.
In practice, revision 4 made equivalence to other marketed devices, also known as predicate devices, more difficult to claim by putting more emphasis on the need for clinical investigations, in line with the requirements of the MDR. Because revision 4 has made equivalence increasingly difficult to claim, more clinical data now have to be generated from clinical investigations.
A press report on implants said that most implants reach Europe without premarket clinical studies, that equivalence lets clinical studies be avoided where equivalent products are already on the market, and that this loophole remained even though from 2020 a manufacturer could submit a CE dossier for an equivalent device only if it held the same information on that device as its own manufacturer and explained how and why it was equivalent. The intensified equivalence approach was already in force, however, through the criteria of MEDDEV 2.7/1 revision 4 of June 2016. Equivalence can still be used to obtain CE certification in rare circumstances where it makes sense, for example where the product changes are only minor, can be sufficiently evaluated with preclinical data and come with planned formal post-approval follow-up studies, particularly for low- to medium-risk devices.