Search hedges are standardized search strategies that can be used to help retrieve relevant articles. They are also sometimes known as search filters, canned searches, clinical queries, or optimal search strategies.
Finding an appropriate search hedge saves the researcher time and eases the task of developing a search strategy from scratch. They can be useful for researchers who need to construct different searches for a systematic review. Some search hedges have been validated for their effectiveness in retrieving relevant results, while others may have been tested but not validated yet for sensitivity, specificity, precision, and accuracy.
Here are some resources for finding search hedges.
Search Hedges by the National Library of Medicine/PubMed:
PubMed Subject Filters
The National Library of Medicine and collaborators have developed subject filters for the following topics: AIDS, Bioethics, Cancer, Complementary and Alternative Medicine, Developmental and Reproductive Toxicology, Dietary Supplements, History of Medicine, Space Life Sciences, Systematic Reviews, Toxicology, and Veterinary Science.
Other resources for finding search hedges:
Search Filters for MEDLINE in Ovid Syntax and the PubMed translation | Health Information Research Unit, McMaster University
Search Hedges LibGuide | University of Alabama at Birmingham