Many who search in PubMed do not find what they seek. Frustrated by off-topic, too few or too many results they look elsewhere for answers. They know they “should” use PubMed as part of finding biomedical information but can’t seem to make it work for them. If that sounds familiar, then read on!
Several alternative search interfaces attempt to solve these problems. Do they work? The answer depends on what you are trying to do. Are you looking for a few good articles? Are you doing exhaustive searches? Are you looking for articles about the psychosocial aspects of biomedicine? To find the right solution for you, it is likely you will need to “test drive” some of the possibilities. Search two or three questions with which you are already familiar, take a look at your results and then decide. This is the first installment of a series of postings in which several of these alternative interfaces will be introduced.
First, let’s be clear about the difference between PubMed and MEDLINE. MEDLINE (Medical Literature Analysis and Retrieval System Online) is a literature database of life sciences and biomedical information. The database has more than 22 million records from approximately 5,200 selected publications from 1950 to the present. MEDLINE is maintained by the National Library of Medicine (NLM). Each record in MEDLINE is manually indexed with NLM’s controlled vocabulary, the Medical Subject Headings (known as MeSH). PubMed is the NLM’s free search interface for the MEDLINE database. However, there are a number of third-party search tools that can be used to access and interact with MEDLINE.
Quertle (the name is derived from the word query) is a website that is a relatively new third-party tool for interacting with PubMed. It was designed by biomedical informatics researchers who wanted a search engine that would be able to pinpoint the most relevant citations for their research. Sign up here for a free account.
Why Quertle? It claims to understand acronyms (e.g., NO for Nitric oxide), have a built-in understanding of biology and chemistry, and understand word relationships. Quertle suggests wording your search using a sentence with subject-verb-object construction. This is a “relationship” search, which we will touch on further below . Quertle also uses Power Terms, e.g., $Disease searches for disease names. The search “caffeine affects what $Diseases” looks for diseases affected by caffeine without have to list each disease. Quertle has many other features, which left me with the question of whether Quertle is that much easier than PubMed to learn.
The recurring example for this series of blog articles: “Is acetaminophen or ibuprofen better for fever control in children?” I would enter the search seen below:
- tylenol or motrin treats fever in children
Quertle yields 2 articles using Focused Results and 189 articles using Broader Results. The same search run in PubMed using MeSH yields 257 hits. The second of the two Focused Results looks promising, but I would like to see a bit more about the topic than this. Quertle sorts by relevance; the first page of Broader Results looks pretty good.
When viewing search results note that Quertle not only retrieves MEDLINE records but also full-text articles from PubMed Central.
Two take home points from comparing Quertle with PubMed:
- Quertle appears to be good at finding a few good relevant articles from MEDLINE.
- The PubMed search engine is better for exhaustive, “leave no stone unturned searches”.
Quertle is definitely worth a look if you don’t mind somewhat of a learning curve and are seeking a few to several good articles about a topic. Here is a quick guide to using Quertle. You can also view this Youtube video.
Future posts in this series will address:
- SUMSearch 2
- TRIP database
- For Mobile devices
- o PubMed on Tap
- o PubMed for Handhelds
- o PubMed Mobile
Installment two will be coming soon. Until then, stay well.
Evans Whitaker, MD, MLIS, Education and Information Consultant for Medicine.