Literature search for medical devices

At least two searches need to be conducted by the manufacturer. One literature search should encompass state-of-the-art literature to identify benchmark devices and, where appropriate, other treatment or diagnostic alternatives. This data should be used as a part of the performance and safety objectives for the device under evaluation. Specifically, based on the state of the art, an indicative list and specification of parameters should be established to determine the acceptability of the benefit-risk ratio for various indications and the intended purpose of the device. 

A second literature search should be conducted on the device under evaluation if it has been previously marketed, or on a device demonstrated to be equivalent. This search aims to identify any favorable or unfavorable clinical data on the device not held by the manufacturer. 

Additionally, a third literature search may be necessary to address pre-clinical aspects, particularly if there are unanswered questions from the clinical evaluation that can be supported by pre-clinical data and scientific evidence.

Choosing the appropriate databases for literature searches is as critical as devising the search strategy itself. Although the MDR does not provide explicit recommendations on selecting literature databases, Article 2(48) mandates the inclusion of peer-reviewed publications. The MDR also mentions utilizing "relevant specialist or technical literature, databases, and/or registers" as sources for collecting available information on devices for post-market surveillance. MDCG 2020-13 (Section D) emphasizes the importance of utilizing multiple databases to reduce bias in the literature review process. 

Furthermore, MEDDEV 2.7/1 Revision 4, Annex 4, provides guidance on selecting appropriate literature databases, recommending MEDLINE, PubMed, and other databases such as Embase, Cochrane CENTRAL trials register etc.  

Additionally, the FDA provides several databases, such as the MAUDE (Manufacturer and User Facility Device Experience) database, which can be useful for post-market surveillance and adverse event reporting. 

Therefore, the decision on which databases to use is left to the authors of the clinical evaluation.

As per MDCG 2020-13, the following literature search documentation will be assessed by the Notified Body during the conformity assessment of the medical device: 

• The literature search protocol. 

• The literature search report. 

• The list of databases used. 

• The full list of retrieved articles. 

• The full list of excluded articles, with reasons for exclusion. 

• Full text copies of all articles selected and analyzed within the clinical evaluation report. 

A rationale should be provided if any of the above is not provided. 

It is important to note that abstracts lack sufficient detail for thorough and independent evaluation but may be sufficient to allow a first evaluation of the relevance of a paper. Copies of the full text papers and documents should be obtained for the appraisal stage. The literature search protocols, the literature search reports, and full text copies of selected documents (including URL links) become part of the clinical evidence and, consequently, the technical documentation for the medical device.