Step 3: Search for Literature
The goal of the systematic literature search is to create a comprehensive search strategy using multiple databases, grey literature, and unpublished studies to find all of the relevant literature. The advanced search features of databases allow you to combine subject terms (i.e. MeSH) as well as keywords to construct a precise, transparent strategy. Search strategies should be sensitive, rather than highly specific. Ask a medical librarian (mclib@uky.edu) for assistance in selecting the appropriate database for your discipline and utilizing the advanced features.
Documentation is the most important step when conducting any review. It is essential that proper documentation be record and reported in order for the methods to be reproducible.
It is important to save:
- your search strategies for reproducibility, transparency, and inclusion in your systematic review manuscript
- the date your searches were run
- and cite any limiters or validated filters used
- the number of results exported
- the number of results before and after deduplication
PRISMA guidelines exist to guide researchers on what to record and report in a protocol, registration, and the final manuscript. In particular, the PRISMA for Searching extension contains 16 reporting items that must be included in order to provide the best methodology.
- PRISMA-SPRISMA-S: an extension to the PRISMA Statement for Reporting Literature Searches in Systematic Reviews
Personal Accounts for Documentation
There are personalized account tools in discipline specific databases such as MyNCBI for PubMed and MyEBSCOhost folder for CINAHL, PsycInfo and other EBSCO databases. These accounts allow you to save searches and document your searching history.
Documentation Tools
- Search Strategies Documentation TemplateThis template will help you record essential information in accordance with the PRISMA-Search Extension.
- PRISMA 2020 Flow DiagramThe flow diagram depicts the flow of information through the different phases of a systematic review. It maps out the number of records identified, included and excluded, and the reasons for exclusions. Different templates are available depending on the type of review (new or updated) and sources used to identify studies.
- Shiny AppThis tool allows you to produce a flow diagram for your own review that conforms to the PRISMA 2020 Statement.
- Database Coverage TableYou must document the platform and coverage of the databases you search for a review. Our librarians update this coverage table yearly to reflect UK Libraries coverage. Feel free to use this table and edit it, but make sure to cite UK Libraries as indicated by the Creative Common License.
Data Management Planning
- CodebookThis codebook has been designed to support your data management planning and organization when conducting systematic reviews and evidence syntheses projects. We recommend placing this document in your main file structure. This will help you meet reporting requirements when you go to publish your research.
- Data Management for Systematic ReviewsLearn about data management planning for systematic reviews and other evidence syntheses. The MCL Librarians cover codebooks, Endnote, and SearchRxiv.
Developing a reproducible and replicable search is the most fundamental aspect of any evidence synthesis. Many published systematic reviews are reproducible and replicable. In order to make your systematic review or evidence synthesis the highest quality, we recommend reviewing our tutorials below and reaching out to one our trained librarians. Many UK Librarians have published quality reviews, so they are excellent resources.
Learn How to Develop Reproducible and Replicable Searches
- Database Searching SkillsExplore this guide to learn core concepts of searching.
- Literature Searches vs Systematic ReviewsWatch this tutorial on the difference between literature searching and advance search methods for various review types.
- Introduction to Systematic ReviewsWatch this tutorial to learn the basics of systematic reviews.
- Translating Searches for Systematic ReviewsEvery database speaks a different "language". Learn the importance of syntax and translation in this tutorial.
- Systematic Reviews Q&AWatch this tutorial to learn more about evidence synthesizes from our medical center librarians.
Tools for Developing & Translating Searches
- PubReMinerTool to analyze sample results from a PubMed search. Can be used to identify MeSH terms, subheadings, journals, and other data of interest to be incorporated into a search strategy or hand search of journals.
- Yale MeSH AnalyzerThis tool extracts MeSH and other citation data from PubMed articles to all you to review terms in a grid for relevant articles to help you develop a search strategy for your review. You can analyze a maximum of 20 articles at a time.
- SR AcceleratorPolyglot is a tool in SR Accelerator that helps with translating searches between various databases.
A Note About Grey Literature
What is Grey Literature?
Grey literature is information produced outside of traditional publishing and distribution channels. It can include clinical trials, reports, policy literature, working papers, newsletters, government documents, speeches, and white papers. Traditionally, systematic reviews include grey literature. This is especially important for systematic reviews including prospective research. Below are some resources available to search for grey literature:
- OpenGreyA search portal for European grey literature. It covers Science, Technology, Biomedical Science, Economics, Social Science and the Humanities.
- Cochrane LibraryCochrane Library is an easy way to search clinical trial registries. You will still have to find the published data and/or studies.
- Google Scholar This link opens in a new windowGoogle Scholar provides an easily searchable interface for searching for grey literature.
Searching for grey literature is difficult. Please feel free to reach out to UK Libraries for help.
- AgeLineIndexing of literature focusing on the population aged 50+ and issues of aging. Includes social gerontology and aging-related content from the health sciences, psychology, sociology, social work, economics, and public policy.
- Applied Social Sciences Index and Abstracts (ASSIA)Indexing and abstracting tool covering health, social services, psychology, sociology, economics, politics, race relations and education. Indexes over 500 journals published in 16 different countries, including the U.K. and U.S.
- Business Source Complete
Provides full-text for thousands of business journals and other sources, peer-reviewed business publications, trade journals/general business magazines, books (most indexed by chapter), industry reports and market research reports.
- CINAHL (Cumulative Index to Nursing and Allied Health Literature) CompleteProvides indexing of the top nursing and allied health literature available, plus the full text for nearly 1,400 journals indexed in CINAHL
- Cochrane LibraryCollection of databases containing independent evidence to inform healthcare decision-making. Includes full-text PDF versions of the Cochrane Database of Systematic Reviews for both complete reviews and protocols.
- Criminal Justice Database (ProQuest)Indexing, abstracting, and selective full-text of research on crime, its causes and impacts, legal and social implications, as well as litigation and crime trends. Coverage includes U.S. and international scholarly journals; corrections and correctional and law enforcement trade publications; and reports, news, crime statistics, and crime blogs.
- EmbaseEmbase is a biomedical and pharmacological database that enables tracking and retrieval of drug information in the published literature.
- ERIC (Educational Resources Information Center) [EBSCOhost]Consists of two files: the Resources in Education (RIE) file of ERIC document citations and the Current Index to Journals in Education (CIJE) file of journal article citations from over 1,000 journals. Both files provide abstracts. In addition, ERIC now contains over 2,200 ERIC Digest records that feature the full-text of the original document. Also provides coverage of conferences, meetings, government documents, theses, dissertations, reports, audiovisual media, bibliographies, directories, books and monographs.
- ProQuest Sociology DatabaseIncludes over 500 titles, with more than 300 available in full-text. Coverage includes anthropology, sociology, social work, political science, policy studies, communication, education, criminology, demography and economics.
- Psychology and Behavioral Sciences CollectionSearchable access to approximately 575 full-text publications, including 550 peer-reviewed journals. In addition to the full-text, indexing and abstracts are provided for all additional journals in the collection.
- PsycINFOProvides access to abstracts, citations, articles, books, and dissertations in the psychological, social, and behavioral sciences. Includes all American Psychological Association journals.
- PubMed (University of Kentucky)Provides abstracts to articles in medicine, nursing, dentistry, veterinary medicine, allied health, and the pre-clinical sciences. Includes biomedical literature from MEDLINE, life science journals, and online books. Also includes links to articles available through UK Libraries' subscriptions.
- ScopusScopus is an abstracting and citation database of peer-reviewed literature that contains over 22,000 titles from more than 5,000 publishers around the world, covering the fields of science, technology, medicine, social sciences, and arts & humanities. Scopus is a citation index which helps in determining the impact of articles and journals by highlighting which titles are most cited within a field.
- Social Work AbstractsProduced by the National Association of Social Workers. Contains references to social work and other related journals on topics such as homelessness, AIDS, child and family welfare, aging, substance abuse, legislation, and community organization. Please note: Limited to four simultaneous users.
- Sociological AbstractsIndexes and abstracts, articles from scholarly journals covering sociology, anthropology, criminology, demography, education, law, social psychology, and urban studies
- Sociological CollectionIndexing full-text articles from 500+ scholarly/peer-reviewed journals back to 1975 in all areas of sociology including social behavior, relationships and social structure. Updated daily.
- Web of Science Core Collection This link opens in a new windowWeb of Science Core Collection indexes primary journals and article citations in several databases spanning a wide range of disciplines.
PRISMA is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses. PRISMA is just a guideline for reporting, it does not account for the entire process. In addition to the original PRISMA standard, there are additional extensions for Scoping Reviews, searching, and protocol development. Below you will find links to various standards and extensions. In particular, view the PRISMA-S to understand how to document and report your search.
- PRISMA-SPRISMA-S: an extension to the PRISMA Statement for Reporting Literature Searches in Systematic Reviews
- The PRISMA 2020 statementAn updated guideline for reporting systematic reviews
- Institute of Medicine Standards for Systematic ReviewsRecommend standards from the search process
- Cochrane Handbook of Systematic ReviewsChapter 4: Searching for and selecting studies
