Refining your search

If too many results are retrieved - Go back over your strategy and NARROW the search:

• Use more specific terms as keywords
• Add terms for other aspects of the questions (e.g. age or gender of the patient), using the Boolean Operator AND
• Use more specific or relevant subject heading terms
• Use limits
• Consider using ‘Focus’ in MEDLINE and Embase (this restricts results to those which have your term as one of the main concepts of the article)

If too few results are retrieved - Go back over the strategy and WIDEN the search:

• Use more terms: synonyms, related terms, broader terms
• Add terms with related meaning with the Boolean Operator OR
• Combine results of thesaurus and keywords
• Use the ‘Explode’ feature of the thesaurus which will include the narrower terms
• Reduce or broaden limits (e.g. date range)
• Select all subheadings of a subject heading term