Inclusion of a search filter on this site is not an endorsement of its validity or a recommendation for its use by the editors of this site, by the InterTASC Information Specialists SubGroup or by the (UK) National Institute for Health and Care Excellence (NICE). For suggestions on the appraisal of filters see the ISSG Search Filter Appraisal Checklist.
This page shows publications that have reviewed search filter performance and individual search filters. It includes filters relating to, for example, but not limited to, specific countries, parts of countries (such as Sub-Saharan Africa), groups of countries (such as OECD, low- and middle-income (LMIC) countries, German-speaking countries) and regions (such as the Eastern Mediterranean), including filters to identify studies published by researchers based in those countries. There may also be relevant filters in the Population-specific page.
Please note that other filter sites/filter collections may have relevant filters for this topic.
Muente C, Pachanov A, Hirt J, Ayiku L, Pieper D. Validated geographic search filters for bibliographic databases: a scoping review. JBI Evidence Synthesis 23(8);2025:1514-1535. DOI: 10.11124/JBIES-24-00395.
The orignal protocol was published here: Muente C, Pachanov A, Hirt J, Ayiku L, Pieper D. Validated geographic search filters for bibliographic databases: a scoping review protocol. JBI Evidence Synthesis 2024;10.11124/JBIES-23-00445.
An abstract with the results of the scoping review and performance data summary is available.
Fulbright H A, Stansfield C. Understanding the performance of geographic limits on Web of Science Core Collection databases, using the United Kingdom as an example. J Med Lib Assoc 2024;112(4):332-340
Muente C, Pachanov A, Hirt J, Hoffmann F, Palm R, Munschek S & Pieper D. Use and application of geographical restrictions in systematic reviews with the aim of including studies about Germany: An update of a methodological review. Health Information & Libraries Journal. 2024: 1–21.
update of Pieper D, Mathes T, Palm R, Hoffmann F. How do authors of systematic reviews restrict their literature searches when only studies from Germany should be included? Zeitschrift fur Evidenz Fortbildung und Qualitat im Gesundheitswesen. 2016;117:1-8.
Ayiku L, Levay P, Hudson T, Finnegan A. The NICE UK geographic search filters for MEDLINE and Embase (Ovid): Post-development study to further evaluate precision and number-needed-to-read when retrieving UK evidence. Res Synth Methods. 2020;11:669-677. doi:10.1002/jrsm.1431
Database indexing changes over time and new vocabulary may be introduced. With older filters, please check the subject indexing to ensure that the subject indexing is still current and, if not, consider whether new vocabulary may need to be added to the filter. Please note that if filters are amended, the performance may change from that published in the original articles and the filter should be reported as amended from the original filter.
FMD(3S)/CHLA OECD countries search filter [2018]
Launch search filter for Ovid MEDLINE (subscribers only)
University of Alberta Library offers filters for various databases / service providers for:
and other regions including:
Cochrane EPOC filter (2023 version) for low and middle income countries. [Cochrane Library: CENTRAL]
Sutton, A. & Campbell, F. The ScHARR LMIC filter: adapting a low- and middle-income countries geographic search filter to identify studies on preterm birth prevention and management. Research Synthesis Methods 2022:1-10 [Cochrane Library]
Sutton, A. & Campbell, F. The ScHARR LMIC filter: adapting a low- and middle-income countries geographic search filter to identify studies on preterm birth prevention and management. Research Synthesis Methods 2022:1-10 [EBSCO]
Canada's Drug Agency Canada filter. {EBSCO] (created 21 January 2022).
Sutton, A. & Campbell, F. The ScHARR LMIC filter: adapting a low- and middle-income countries geographic search filter to identify studies on preterm birth prevention and management. Research Synthesis Methods 2022:1-10
Pachanov A, Muente C, Hirt J, Pieper D. Translation and validation of a geographic search filter to identify studies about Germany in Embase (Ovid) and MEDLINE(R) ALL (Ovid). Research Synthesis Methods. 2025;16(4):688-700.
see also Conference paper presented at the EBM Congress 2025.Cochrane EPOC filter (2023 version) for low and middle income countries. [Ovid]
Canada's Drug Agency provides broad (sensitive) and standard Canada filters. This is for a multifile search of MEDLINE, Embase and PsycINFO in Ovid. Last updated 16 December 2021 and 21 Janaury 2022.
Sutton, A. & Campbell, F. The ScHARR LMIC filter: adapting a low- and middle-income countries geographic search filter to identify studies on preterm birth prevention and management. Research Synthesis Methods 2022:1-10 [Ovid]
Ayiku L, Hudson T, Williams C, Levay P, Jacob C. The NICE OECD countries' geographic search filters: Part 2-validation of the MEDLINE and Embase (Ovid) filters. J Med Libr Assoc. 2021;109(4):583-589. [Ovid]
Ayiku L, Levay P, Hudson T. The NICE OECD countries’ geographic search filters: Part 1—methodology for developing the draft MEDLINE and Embase (Ovid) filters. J Med Libr Assoc. 2021;109(2):258-266
The final versions of the filters are available in Appendix 3.
There is an ISSG critical appraisal for this filter.
Ayiku L, Levay P, Hudson T, Craven J, Finnegan A, Adams R, Barrett E. The Embase UK filter: validation of a geographic search filter to retrieve research about the UK from Ovid Embase. Health Info Libr J. 2019;36(2):121-133. doi:10.1111/hir.12252. Epub 2019 Mar 25.
Launch filter in Ovid Embase (subscribers only)
This filter is available to download as a Word document.
FMD(3S)/CHLA SubSaharan Africa search filter [2014]
Launch filter in Ovid Embase (subscribers only)
Pachanov A, Muente C, Hirt J, Pieper D. Translation and validation of a geographic search filter to identify studies about Germany in Embase (Ovid) and MEDLINE(R) ALL (Ovid). Research Synthesis Methods. 2025;16(4):688-700.
see also Conference paper presented at the EBM Congress 2025.Cochrane EPOC filter (2023 version) for low and middle income countries. [Ovid]
University of Pittsburgh Health Sciences Library. Filters for limiting to studies conducted in the USA or researchers in US institutions (updated in 2025).
Library and Digital Information Networks, World Health Organization. WHO country filters for LMIC countries, v3. Zenodo: March 2024. [PubMed]
Provides filters for each low and middle income country based on the World Bank country classification
Pachanov A, Münte C, Hirt J, Pieper D. Development and validation of a geographic search filter for MEDLINE (PubMed) to identify studies about Germany. Res Synth Methods. 2024. doi: 10.1002/jrsm.1763. [PubMed]
Also published as a preprint. Pachanov A, Münte C, Hirt J, et al. Development and validation of a geographic search filter for MEDLINE (PubMed) to identify studies conducted in Germany. Authorea. March 15, 2024.
Cochrane EPOC filter (2023 version) for low and middle income countries. [PubMed and Ovid]
Cheung A, Popoff E & Szabo S M. Application of text mining to the development and validation of a geographic search filter to facilitate evidence retrieval in Ovid MEDLINE: An example from the United States. Health Information & Libraries Journal 2022:1– 12.
Earlier presentations of this filter
Cheung A, Popoff E, Szabo S M. Using text-mining to develop a US-specific geographic search filter to facilitate systematic reviews in MEDLINE. In: Advances in Evidence Synthesis: special issue. Cochrane Database of Systematic Reviews 2020;(9 Suppl 1): 318. From the abstract there is a link to a preliminary search filter.
Popoff E, Cheung A, Szabo S. PNS46 Application of Text Mining to the Development of a Geographic Search Filter to Facilitate Evidence Retrieval in Ovid Medline. Value in Health. 2020;23 (Supplement 2):S651. This is a conference abstract reporting on a filter to identify research from the USA in Ovid MEDLINE. The filter itself is not reported in the abstract.
Sutton A & Campbell F. The ScHARR LMIC filter: adapting a low- and middle-income countries geographic search filter to identify studies on preterm birth prevention and management. Research Synthesis Methods 2022:1-10 [Ovid]
Canada's Drug Agency
broad (sensitive) and standard Canada filters. This is for a multifile search of MEDLINE, Embase and PsycINFO in Ovid. Last updated 16 December 2021 and 21 Janaury 2022.
There is a "standard" filter for PubMed MEDLINE. Last updated March 2012.
University of Alabama at Birmingham. United States filter (work in progress) [PubMed]
Launch PubMed search here
Ayiku L, Hudson T, Williams C, Levay P, Jacob C. The NICE OECD countries' geographic search filters: Part 2-validation of the MEDLINE and Embase (Ovid) filters. J Med Libr Assoc. 2021;109(4):583-589. [Ovid]
There is an ISSG critical appraisal for this filter.
Ayiku L, Levay P, Hudson T. The NICE OECD countries’ geographic search filters: Part 1—methodology for developing the draft MEDLINE and Embase (Ovid) filters. Journal of the Medical Library Association. 2021;109(2):258-266
The validated and final versions of the filters are available in Appendix 3.
FMD(3S)/CHLA Canada search filter [2018] [Search filters available for MEDLINE via EBSCO, OVID]
Tadmouri GO, Mandil A, Rashidian A. Development of an Eastern Mediterranean Region search strategy for biomedical citations indexed in PubMed. East Mediterr Health J. 2017;23(9):619-629. [PubMed]
Ayiku L, Levay P, Hudson T, Craven J, Barrett E, Finnegan A, Adams R. The MEDLINE UK filter: development and validation of a geographic search filter to retrieve research about the UK from OVID MEDLINE. Health Info Libr J. 2017;34(3):200-216. {Ovid]
The search launch for Ovid MEDLINE (subscribers only)
The 2019 version of this filter is available to download as a Word document.
There is an ISSG critical appraisal for this filter.
Campbell S, Dorgan M, Tjosvold L. Creating provincial and territorial search filters to retrieve studies related to Canadian indigenous peoples from Ovid MEDLINE. J Can Health Libr Assoc. 2014;35(1):5-10.
FMD(3S)/CHLA SubSaharan Africa search filter [2014]
Launch the search filter in Ovid MEDLINE
Pienaar E, Grobler L, Busgeeth K, Eisinga A, Siegfried N. Developing a geographic search filter to identify randomised controlled trials in Africa: finding the optimal balance between sensitivity and precision. Health Info Libr J. 2011;28(3):210-5. doi: 10.1111/j.1471-1842.2011.00936.x.
Radut D S, Sanz-Valero J. Developing and testing of search filters for the new European Union Member States' research. Health Info Libr J. 2010;27:227-234. doi: 10.1111/j.1471-1842.2010.00903.x
Valderas JM, Mendivil J, Parada A, Losada-Yanez M. Development of a geographic filter for PubMed to identify studies performed in Spain. Rev Esp Cardiol. 2006; 59(12):1244-51.
Launch the search filter in PubMed
Cabello JB, Emparanza JI, Ansuategi E. Improving literature searches. Geographic filters, methodology filters. Two different algorithms, two different applications. Rev Esp Cardiol. 2006; 59(12):1221-4. This is an editorial on Valderas et al.
University of Pittsburgh Health Sciences Library. Filters for limiting to US studies
Ovid APA PsycInfo Search Filters (updated 22 April 2024)
Sutton, A. & Campbell, F. The ScHARR LMIC filter: adapting a low- and middle-income countries geographic search filter to identify studies on preterm birth prevention and management. Research Synthesis Methods 2022:1-10 [Ovid]
Canada's Drug Agency provides broad (sensitive) and standard Canada filters. This is for a multifile search of MEDLINE, Embase and PsycINFO in Ovid. Last updated 16 December 2021 and 21 Janaury 2022.
Fulbright H A, Stansfield C. Understanding the performance of geographic limits on Web of Science Core Collection databases, using the United Kingdom as an example. J Med Lib Assoc 2024;112(4):332-340
Hirt J , Buhtz C, Meyer G, Balzer K. [Publications German-speaking countries in high impact journals: development and validation of a search filter]. Publikationen aus dem deutschsprachigen Raum in Zeitschriften mit hohem Impact Factor: Entwicklung und Validierung eines Suchfilters. Pflege 2018;31:1–10.
NOTE: corrected translation of the original title from German into English: Publications from German-speaking countries in journals with a high Impact Factor: development and validation of a search filter
NOTE: The filter appears in (Abbildung 3, pg 6, "instruction for use of the search filter"):
1. Öffnen des lizenzierten Zugangs von Web of Science (hier: Advanced Search).
2. Eingabe der folgenden Suchstrategie (Kurznamen der High Impact Journals) AND (Suchfilter):
(SO=("INT J NURS STUD" OR "J ADV NURS" OR "J CARDIOVASC NURS" OR "J NURS MANAGE" OR "J NURS SCHOLARSHIP" OR "NURS OUTLOOK" OR "RES NURS HEALTH" OR "WORLDV EVID-BASED NU" OR "AM J CRIT CARE" OR "BIRTH-ISS PERINAT C" OR "CANCER NURS" OR "ONCOL NURS FORUM")) AND (OO=nursing OR AD=nursing)
3. Eingrenzen der Publikationsformate auf "Review" und "Article" sowie der Herkunftsländer "Austria", "Germany" und "Switzerland"