Physical Therapy: Search Tips

The PTNow blog recently featured a two-part blog post entitled "10 Tips for Smarter Searching." These posts offer some great tips for searching the PT literature and summarize much of what is covered on this LHL guide.

• Part 1
• Part 2

Put your clinical question into the PICO format.

Brainstorm and jot down keywords for each part of your question. Try to think of every possible way an author/researcher might refer to your topics. Cross out words that aren't working and add to this list as you search. Use this PICO Worksheet  if you'd like.

Keep a search log or print your search history. This will keep you from re-running the same searches and help you track how you've had to adjust your search.

Click the image below to view a 4-minute tutorial explaining how to use Boolean operators (AND, OR, and NOT) to build a search statement.

Use an asterisk (*) after the root of a word to search for variant endings. For example, assess* will find assess, assessment, assessed, assessing, etc. This is called truncation.

Image source: www.indianjurol.com/viewimage.asp?img=IndianJUrol_2011_27_4_536_91448_f3.jpg

Following Sackett's levels of evidence for intervention (shown above), Cochrane Library is a good database to start with because it indexes the types of articles (i.e., systematic reviews) that are considered the highest level of evidence. These reviews synthesize the literature on a given topic and provide a synopsis that tells what the general consensus of the literature is for a given treatment.

Don't be surprised or discouraged if you don't find a systematic review in the Cochrane Library on your topic. Cochrane is best for well-researched interventions for which many studies have been done. Newer types of treatments or interventions are not likely to be covered yet by Cochrane.

The following article provides a nice explanation of Sackett's Levels of Evidence within the context of physical therapy:

All Evidence is Not Created Equal: A Discussion of Levels of Evidence by Steven Glaros, PT Magazine (2003).

Searching by subject instead of keyword (words that you come up with yourself) is a way to quickly do a very focused search. Here are the key differences between searching by subject terms and keywords:

Keywords

• Words that appear in the database record (i.e., article title, abstract, journal title, authors, author's affiliation, etc.)
• Up to YOU to come up with the terms authors may have used to refer to a topic
• Consider using truncation (* symbol) to capture different word endings (e.g., stretch* to find stretching, stretch, stretches, etc.)
• Searches using keywords are typically fast and easy and, for normal searches, may lead you to a sufficient number of relevant articles
• However, keyword searches are also more likely to retrieve articles that are not truly about the keywords; the terms may only be mentioned once in the article record or may be used in a different context than you intended (e.g., AIDS will also retrieve articles on hearing aids, audiovisual aids, clinical aids, teaching aids, etc.)

Subject Terms

• Help you retrieve articles based on subjects, not words
• Are standardized, which is helpful because they consolidate different words used to describe the same concept (e.g., teen, teens, teenager, adolescence, etc.) into one standardized term (e.g., Adolescent)
• Added to database records by professional indexers who have read each article to determine what it is truly about
• AKA: Descriptors, MeSH Terms (Medical Subject Headings), CINAHL Headings, index terms, controlled vocabulary, thesaurus, major concepts, etc.
• Searching by subject headings will often yield a more focused set of results because your search is limited to the relevant subject(s)
• Subject headings are hierarchical, which makes broadening and narrowing a search much easier

Databases include an area where you can browse/search their entire list of subject terms (e.g., MeSH Database in PubMed). You may not find subject terms appropriate for your topics, and that is fine. Or you may wish to combine keywords and subject terms. Here's an example:

Child Development Disorders, Pervasive[MeSH] AND therapy ball chairs

The first term is a subject term; the "MeSH" notation behind it tells PubMed to search only for articles that have been tagged with this subject term. The second term is a keyword phrase for which there is no good MeSH term.

Tips for broadening your search:

• Try using synonyms for your original search terms
• Explore related or broader topics (e.g., exercise therapy instead of stretching). Don't forget you can refer to PubMed's MeSH Database or CINAHL Headings look-up to see the term tree/hierarchy
• Remove less critical search terms from your search
• Remove some search filters/limits
• Reconsider your inclusion/exclusion criteria
• Consider searching by keywords instead of subject terms

Tips for narrowing your search:

• Add additional search terms to your search statement
• Explore filter/limit options in the database (e.g., date range, publication types, age range, etc.)
• Focus on a specific aspect of your broader question. Consider applying subheadings (e.g., adverse effects, rehabilitation, therapy, etc.) to MeSH terms and CINAHL Headings
• If your initial search was a keyword search, try a subject heading search instead
• Limit to articles where your subject headings are a "major" focus (possible only in PubMed & CINAHL)
• If you are doing a keyword search, search for terms only in the Title or Abstract