Use specific words of natural language or terms from a thesaurus.
Add a new search term from CINAHL Headings or natural language. Link the new term with the narrowing AND connector.
If you have used a CINAHL Heading from the thesaurus, you can narrow down the results by checking the Major Concept box. Thus, you need to rebuild the search. If you have used several CINAHL Headings, you can do a test using the Major Concept limit with one heading at first. If you still get too many results, you might add the Major Concept limit to all subject headings.
Check that you have not used ambiguous terms or abbreviations.
Limit the search by language, publication year or document type.
Too few references?
Decrease terms connected with the AND connector.
Add synonyms, related or broader concepts to the search phrase using OR connector.
Notice that some words have different spellings. E.g. spellings in American and British English may vary.
Truncate the search term or decrease the number of letters before the truncation.
Instead of specific search terms, use more common words of natural language or broader terms from a thesaurus.
Broaden the search by language, year of publication or document type.
Is CINAHL the right database for your topic? Consider PubMed and other databases also.