Faculty of Health and Medical Sciences

Find the best evidence

Troubleshooting your search

Once you have developed a search strategy and selected your clinical resource, the next step is to implement your search. You can apply additional search tools and limits depending upon the features available in the clinical resource.

Example search string:

Not finding enough information?

This could indicate several different things:

  • It may be the result of a simple problem. Check that there are no incorrect spelling or typos in your search terms.
  • Perhaps your search strategy is not well constructed e.g. you’ve put brackets or phrase marks in the wrong places, or used Boolean operators incorrectly (AND, OR, NOT).
  • Perhaps you are searching a database that doesn’t cover the information you require. Go back to the pyramid and access resources from lower down in the pyramid hierarchy.
  • You may need to consider re-focussing your clinical question
  • Perhaps your question is unanswerable?
  • Your topic is very specialised or may even be impossible to answer. You may need to consult with an experienced clinician for advice on whether your question is answerable, or whether you have selected the appropriate interventions, comparators and outcomes.
  • If you are concerned about whether your question is answerable or not, try to think of a study design that could answer your question. If you are unable to mentally ‘design’ an appropriate study, perhaps your question should be refocussed.

Techniques for increasing

  • Use OR to include synonyms /related terms and therefore expand the search.
  • Include all languages (English abstracts may be available).
  • Remove all limits.
  • Do not restrict to publication types.
  • Choose all subheadings.
  • Use a broader term e.g. eye diseases instead of retinal diseases.
  • Remove major focus limit.
  • Explode term to include more specific terms.
  • Use truncation to expand search terms.

Finding too much information?

This could indicate that:

  • You need to search in a more specific database.
  • Your question is too broad and needs to be refocussed.
  • Perhaps you need to use some more search techniques and tools that will help you to narrow your search. Refer to Techniques for limiting or expanding your search for suggestions on how to narrow your search.

Boolean operators: try combining more search terms using the Boolean operator “AND”. For example – if your research is focusing on Australia you might like to narrow your search by including a geographic term e.g. diabetes AND Perth.

If you find your search results are including subject areas which are not of interest, you can filter these out using the “NOT” operator between terms. Use “NOT” with caution as its application will also exclude all results that include both terms.

Phrase searching: putting quotation marks around a string of keywords tells the database to search for those terms as a phrase only. This can be really useful for multi-word terminology such as “cardiac failure” or “adjuvant chemotherapy”.

Using search limits: make sure that you have made use of the search limits available to you in the particular database.

Techniques for limiting

  • Use AND to combine with another concept and limit your search.
  • Language limit to English.
  • Limit by Age, Sex, Human.
  • Publication type limit to Randomised Controlled Trial, Review.
  • Subheadings limit to Diagnosis, Therapy.
  • Use a more specific term eg Femoral neck fractures instead of hip fractures.
  • Apply major focus to MeSH.
  • Do not explode term.
  • Use the full text word in the search.
  • Limit to subsets e.g. Core clinical journals.