Searching for Health Information Online (Part 4)
PubMed is a service of the National Library of Medicine. It is a search engine of the MEDLINE database, which covers over 5,000 biomedical journals dating back to the 1950's. Searching PubMed allows access to the primary medical literature for healthcare professionals and patients interested in recently updated, technical information.
PubMed has many advantages. It's more frequently updated than many other databases (citations can even be found that are "in process" and haven't yet been formally added); and it's powerful and customizable. However, for the busy clinician with little formal training in searching the medical literature, PubMed can be difficult to use, and therefore its powerful features are often wasted. And if professionals have a difficult time using it, then non-professionals and patients will also likely have a tough time.
Google Scholar is an attempt to preserve the power of PubMed, add additional features, and present the search interface simply. The advantages include:
- Papers are listed not in order of publication, but in order of relevance, which is determined by PageRank, the same system used in regular Google searches.
- Next to each publication is a link to other publications that cite it. This allows you to immediately determine whether a paper is influential and who it has influenced.
- Scholar also includes searches of publications that don't make it to Medline, like books, small journals, and private collections.
- Scholar uses the familiar uncluttered Google interface.
PubMed initially only provides one link. After clicking on "show related searches," it expands the search and provides 100 entries in no obvious order.
Next, he searches Google Scholar for ["kidney stones" AND lemonade]:
While Google Scholar only provides 73 results, the results are listed in order of importance, and it's easy to see at a glance how many times each paper is cited by other papers.
This is a critical feature. First, it instantly introduces you to some of the most important papers in the field. Second, it allows you to follow the web of citations in the medical literature. Almost without exception, every published physician and scientist I've seen encounter Google Scholar for the first time has immediately "Scholared" themselves to see who is citing and reading their work.
Of course, as useful as Google Scholar is, it's not perfect. For an overview of the advantages and disadvantages of using Google Scholar see this discussion from the McMaster Health Sciences Library. And for more discussion of Google Scholar and searching the medical literature, see Dean Giustini's Google Scholar Blog.
Lastly, if you have access to a medical library, I encourage you to take advantage of it and learn from the people who work there.