Systematic reviews: Evaluation of search result

Literature search process

Evaluation of the search results

Any literature search requires you to evaluate the search result. Have you achieved results that enable you to answer your research question? Is your literature search both inclusive and comprehensive? Review the early results of your search. Are core articles for your topic found in the search results?

Evaluation of search results

Your search resulted in a lot of hits:

Combine your terms using AND.
Use phrase searching (excact phrase).
Use narrower or more specific terms.
Utilize the way the databases structures its subjects/topics.
Limit ti year, language, etc..
remove terms completly from your search using NOT (use with caution).

Your search resulted in few hits:

Use truncation (put * or ? at the end of the word to search for multiple forms of the word).
Use broader terms to expand the search.
Combine key concepts in other ways.
Break-up compound words into multiple words.
Combine synonyms with OR.

How to evaluate the search

One way to evaluate whether your search has yielded a reliable search result or not, is to use core articles which you would expect to find in the search results. Search for the article in your search results. Does it appear in the results? If not why not? Look at how the article is indexed to find indexing and free text terms that will help you identify it in future searches.

If you have a very large set of results, combine the results of your final search set with the title title/author of your core article using AND. If your search strategy does not capture the article, look at the article title, abstract and keywords and compare with your keywords and customize the search strategy.

Peer review of the search

Cochrane Handbook for Systematic Reviews of Interventions recommends that you get your search strategy peer-reviewed before performing the search to ensure a high quality of the search.

PRESS guideline and checklist provides a number of recommendations on how to evaluate a search strategy

McGowan J, Sampson M, Salzwedel DM, Cogo E, Foerster V, Lefebvre C. PRESS Peer Review of Electronic Search Strategies: 2015 guideline statement. J Clin Epidemiol. 2016 Jul;75:40-46

McGowan J, Sampson M, Salzwedel D, Cogo E, Foerster V, Lefebvre C. PRESS Peer Review of Electronic Search Strategies: 2015 Guideline Explanation and Elaboration (PRESS E&E) PRESS – Peer Review of Electronic Search Strategies: 2015 Guideline Explanation and Elaboration (PRESS E&E). Ottawa: CADTH; 2016 Jan.