Cochrane Handbook see chpt 4, “Searching for and Selecting Studies” (pp. 67–107)
Finding What Works in Health Care: Standards for Systematic Reviews see chpt 3, “Standards for Finding and Assessing Individual Studies” (pp. 81–153)
PRISMA-S checklist a checklist for reporting literature searches in systematic reviews
1. Construct a search strategy using the search syntax of each database and include appropriate synonyms. If the database uses subject headings, use a combination of relevant subject headings and keywords.
2. Search filters may be appropriate if you want to limit to specific methodologies or population groups (see ISSG Search filters)
3. Save search strategy (see instructions 'Saving your search strategies' box below)
4. Run search and adapt syntax to features of each individual database
5. Exports results to a reference manager, for example, EndNote or Zotero
6. Remove duplicates - see Bramer et al. (2016) for a duplication method using EndNote
7. If you are using screening software, export results to your chosen program, for example, Covidence
Many databases use Subject Headings as an aid to searching. Subject headings describe the content of an article, each article might have multiple headings. Subject headings are specific to each database. A comprehensive search will use both subject headings and keywords for each concept.
MeSH (Medical Subject Headings) are used in Medline, PubMed and the Cochrane Library.
Yale MeSH Analyzer is a tool to identify search terms from Medline see this introductory video
Document your search strategy and include it in your systematic review so it can be reproduced for verification. For each database you search, record:
– The database name and platform, for example, Medline (Ovid)
– Date search was run
– Full search strategy, including limits used and date range
– Number of studies found
Save the search strategy in each database with the ‘save search’ feature. You may need to rerun the search strategies if the original search was run more than 12 months before completion of the SR.
Templates, like the Search Results Summary (from Cochrane’s EPOC resources for Authors) are a useful tool to record search strategies.
If you would like to narrow your search to a particular population or by a particular methodology the ISSG (InterTASC Information Specialists' Sub-Group) have a list of appraised search filters ISSG Search Filters Resource
SuRe Info (Summarized Research in Information Retrieval for HTA) contains resources and tips for searching for systematic reviews in health sciences and health technology assessments. Includes: sources to search, designing search strategies, search filters, documenting and reporting the search process and more.
Some filters can be 'launched' in Medline and EMBASE. This means you won't have to type in each line of the search filter into your search.
If you're looking for a Medline RCT search filter, this article which reviews a range of filters:
Glanville J, Kotas E, Featherstone R, Dooley G. (2020). Which are the most sensitive search filters to identify randomized controlled trials in MEDLINE? Journal of the Medical Library Association, 108(4), 556-563. https://doi.org/10.5195/jmla.2020.912