There may be times when you wish to search for journal articles that are set in a United Kingdom context, or look at UK populations or practice. This can be quite difficult to do as even UK journals and authors may publish articles about other countries' practices, and articles about UK practice may not make it explicit in the title or abstract that they are about the UK.
Recently, a search filter was published in the Health Information and Libraries Journal by Lynda Ayiku et al of NICE that attempts to locate any articles that are about UK research, populations or practice in Medline, and exclude others. The full search filter is validated, meaning it has been tested against a gold standard set of references to make sure it works.
The search filter was designed for the Ovid version of Medline, and below is a simplified version based on their interim search strategy, which can be copied and pasted into the search box on Ovid, and then combined with your subject search (using 'and') to filter your search to UK articles only.
Simplified search filter for use in Medline using the Ovid interface
exp United Kingdom/ OR (national health service* or nhs*).ti,ab,in. OR (english not ((published or publication* or translat* or written or language* or speak* or literature or citation*) adj5 english)).ti,ab. OR (gb or "g.b." or britain* or (british* not "british columbia") or uk or "u.k." or united kingdom* or (england* not "new england") or northern ireland* or northern irish* or scotland* or scottish* or ((wales or "south wales") not "new south wales") or welsh*).ti,ab,jw,in. NOT ((exp africa/ or exp americas/ or exp antarctic regions/ or exp arctic regions/ or exp asia/ or exp oceania/) not (exp united kingdom/ or europe/))
Whilst not quite as good as the full filter, it still has good recall (although it may miss a few references and should not be relied upon for systematic reviews) and may be an easy way to get rid of a lot of unwanted references.