Search filters and clinical queries

Search filters, sometimes known as clinical queries or hedges, are preā€‘made search strategies on study design (methodology) or on certain topics that you can include in your search to save time. Filters may be designed to increase sensitivity (recall), or to be precise.

Search filters are database/platform specific.

Some sources of search filters

BMJ Best Practice Search Strategies
Systematic review and RCT search strategies designed in-house by BMJ Knowledge Centre information specialists. These strategies are designed for Ovid databases.

CADTH (Canadian Agency for Drugs and Technologies in Health)
Filters include: economic evaluations; health technology assessments; health utilities/quality of life; minimally clinically important difference (MCIS).

Health Information Research Unit (HIRU), McMaster University
Filters include: therapy; diagnosis; review; prognosis; causation (etiology); economics; cost; clinical prediction guides; qualitative.

ISSG (InterTASC Information Specialists' Sub-Group) search filters resource
Filters are grouped by study design or focus on certain topics. Filters include: guidelines; health applications (apps); knowledge translation; population group filters (including prehospital/emergency care, pregnancy, sexual minorities, immigrants, indigenous peoples, people with disabilities, ethnic groups); quality of life.

Lowitja Institute
Provides access to Aboriginal and Torres Strait Islander health literature on PubMed.

Ovid Expert Searches
These pre-defined searches will run a search and take you directly to the results in Ovid databases. Topics include COVID-19, sepsis, childhood obesity, infectious diseases, and more. No login required on site; an OpenAthens account is required for off site access.

PubMed Clinical Queries
Use to refine PubMed searches on clinical or disease-specific topics.

SIGN (Scottish Intercollegiate Guidelines Network)
Search filters on systematic reviews, randomised controlled trials, observational studies, diagnostic studies, economic studies and patient issues.


"All search filters and all search strategies are compromises, and an assessment of the performance of filters for your own research should always be made."

-The InterTASC Information Specialists' Sub-Group 2022, ISSG Search Filter Resource, accessed 18 August 2022.


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