A systematic review literature search attempts to identify all relevant evidence that addresses a clearly defined research question, using a transparent, comprehensive, and reproducible methodology. This means the search must be:
- Systematic: following a structured, pre-defined protocol to minimize bias.
- Comprehensive: Including multiple databases to capture all relevant studies. Carpenter Library typically includes Ovid Medline, Embase, Web of Science, and Cochrane. CINAHL and PsycInfo are used when appropriate.
- Transparent: Clearly documenting the search strategy, including databases searched, search terms, limits used, and dates of searches.
- Reproducible: Providing enough detail so that another researcher could replicate the search and obtain similar results.
This rigorous approach ensures that the review reflects the totality of available evidence, reduces the risk of selective reporting, and supports the validity and reliability of the review’s conclusions.
Techniques used in search strategies:
- Librarians ask review teams to supply some relevant articles when beginning a review. These articles are examined in databases to find the subject headings applied. These are used in building a atrategy.
- Use concepts from the research question as building blocks for the strategy.
- PICO includes outcomes. These are not always included in the strategy.
- Carpenter librarians begin the search in one database, typically Ovid Medline, and translate to the other databases.
- The strategy utilizes subject headings and keywords in combination to form concepts.
- Keywords are synonyms, acronyms, and word variants of subject headings.
- Truncation of keywords is used to include word variants (including plurals, British spellings, misspellings, etc.) in the search without having to type each one.
- Subject headings are arranged in hierarchical lists called trees (eg. MESH headings in PubMed; How MESH Works). Headings listed higher in the tree include all the headings listed under them. Librarians select headings based on their position in a tree to make searches broader (more sensitive) or narrower (more specific) in an attempt to include all relevant studies yet minimize including irrelevant studies.
- Concepts are combined using "Boolean" operators (and, or, not). Subject headings and keywords within a concept are combined in a string with "or" to include results from all the terms in the string. Concepts are combined in a string with "and" to yield results with only articles including each concept. The "not" operator is used in a string to exclude certain results from a search string.
Submit Systematic Review Request Form to initiate a systematic review consultation.
