Literature Search Tips for Conducting a Clinical Evaluation Report

Introduction

The Clinical Evaluation Report (CER) is substantially based on data retrieved from the professional literature. A summary of the scientific literature related to device-specific pivotal data and contemporary state of the art literature should be incorporated.

The following sections elaborate on simple methods to guarantee a qualified literature review process.

Search Strategy

The information gathered is interrelated but requires two separate searches to be conducted:

• ‘Pivotal Data’ search – this is research about the safety and performance of the specific device(s) and/or the equivalence device(s).

• ‘State of the Art’ – research related to the state of the art technology, mechanism of action, general adverse or side effects, safety and performance of the device(s) in this category but not limited to the device(s) under review.

Dividing the search process into two primary searches is essential for promising the wanted results for the different chapters for the CER.

Keywords

The search strategy and keywords will be different for each search:

• Pivotal Data search – Keywords will be the specific name of the device (s) and the manufacturer.

• State of the Art search – Keywords will be generated from ‘PICO’ elements (as presented in Table 1 below):

Table 1: PICO Elements

​Criteria	​Description	Search Terms / Keywords
P	​Population, patient, and problem Who are the users, patients, or community being affected? What are symptoms, age, gender, etc.?	The information is covered under the ‘Intended Purpose’
I	Intervention What is being done for the population? (e.g. screening, surgery, rehabilitation, etc.)	The information is covered under the ‘Intended Purpose’
C	Comparison Is there a control group or comparison? (e.g. different treatment options, placebos, etc.)	This may be an alternative treatment option
O	Outcome What do we anticipate as an outcome?	Adverse event Adverse effect Or keep this blank to enable analysis of all applicable outcomes

• Look for any additional keywords in review papers or research studies – these are usually listed at the end of the abstract.

Conducting Database Searches

Once you have generated the keywords for each search strategy, use at least two databases. PubMed (https://pubmed.ncbi.nlm.nih.gov/) and Cochrane Library (https://www.cochranelibrary.com/) are freely available and easy-to-use databases for scientific research.

• Create a user profile on each database and save your search. This is very important as you will be able to update your literature reviews quickly and easily for each reporting period by simply re-running the searches, limiting the timeframe from the date of the previous search to the new reporting time. Make sure the search is saved with the correct name of the search and the date that the search was conducted.

• Start searching widely and then narrow down your search. Connect keywords using the Boolean Operator ‘OR’ – this will generate many hits but then by combining terms using ‘AND’ and applying filters, the number of articles found will be reduced significantly (Figure 1).

Figure 1: Search Procedure

• Use referencing manager software. There are many freely available referencing managing products such as Mendeley, Zotero and the citation manager in Word. When you have the results of your search you can directly export them into your reference manager from the database search. Once the references are in the reference manager, you can remove duplicate references. You can also store PDFs of articles in the reference manager. Creating different folders for each search that you conduct allows you to store all relevant articles together. You are also able to move references between the folders by simply copying and pasting the citations. The reference manager can be used to create a professional reference list for your CER.

• Keep a record of the number of hits for each database search or hand search that you conduct. This information is needed when producing a flowchart to illustrate the results of your searches for the CER.

• Export your citations from your database search into a spreadsheet. In PubMed, it is possible to export the results of your search to an Excel spreadsheet (.csv). Once you have this information on a spreadsheet you can use this spreadsheet to report whether the article was included in the review or if it was excluded with reasons. This information can simply be converted to a table and added to the CER.

Summary

Conducting literature reviews can be challenging. Being systematic and diligently recording the findings of database searches and saving the search strategies will save you time in the future and assist you in generating subsequent CERs.