Here are some tips for finding the best search terms:
1. Identify synonyms
To identify more search terms, go back to the PICO(D) elements of your question and list all the synonyms you can think of for your population, intervention, and comparators of interest. For help, you can consult with experts in the field, librarians, and even a thesaurus.
2. Look for related search strategies
One good way to find relevant terms is to identify one or two systematic reviews on your topic or a similar topic. Ideally, the researchers will have a published description of their search strategy, which can be a starting point for your own search.
Keep in mind that your research question probably won’t match theirs exactly, so you will have to remove keywords that aren’t relevant and add additional terms that weren’t included.
You might also borrow elements of a few search strategies and combine them together. For example, one systematic review may give you population terms, but another may be better for intervention terms.
3. Search for MeSH terms
Finally, for every concept term (e.g. heart attack) in your research questions, you’ll want to find terms in the controlled vocabulary of your chosen database. For MEDLINE, you will use the Medical Subheadings (MeSH) database to find “indexed terms.”
We’ll talk more about MeSH terms on the next page.