The short item I wrote about cancer immunotherapy quickly went viral on Monday and became the most-read article on Scientific American’s website. Seems like a good time to show folks interested in conducting their own medical searches how much deeper they can get into the topic on their own—if they know how and where to look.
Readers of my series of posts about online medical searching know how much I like PubMed. But I wonder if the folks at the National Library of Medicine (NLM) have ever thought of using the two shortcuts I’m about to describe?
Let’s say you’ve found an article that you’re interested in and, for argument’s sake, let’s say it’s the feature article about cancer immunotherapy that Jedd Wolchok wrote for the May issue of Scientific American. (It also happens to be the article I pointed to with my blog post.)
You want to know what else there is in the scientific literature about this topic—but you don’t want to go through thousands and thousands of links to find the best hits.
The first trick lets you do a broad search without getting overwhelmed.
The second trick lets you do a narrower search that tells you who else has done closely related research.
The Broad Search
The Trick: Find the PubMed entry for the article that you thought was so helpful and then click on the related citations link just below it, which allows the NLM’s own structured data algorithms to do the searching for you.
2. Where the first box says “All Fields,” use the drop-down menu to pick Author and type in “Wolchok.” (Notice how the term auto-completes; always a good sign.)
3. Hit return and you have every article in the scientific literature in which someone named Wolchok was either the sole author or a co-author.
4. And right there at the top of the list is “Cancer’s Off Switch,” by Wolchok JD in Scientific American. (No, not every consumer magazine is indexed by PubMed, but ours is; tells you something right there—doesn’t it?)
5. Notice that the last line of the entry includes a link for “Related Citations” and click on that. Up comes a bunch of articles that gives you a broad range of articles in which researchers are trying out different ways of stopping a tumor’s growth or spread—from the original article on immunotherapy, to destroying a tumor’s blood vessels to starving a tumor of glucose. Each entry going down the list goes a little farther afield than the one above it.
Obviously you can start with any article—as long as it is indexed on PubMed (And why would you trust an article that’s not on PubMed?). I tend to do this kind of search when I have found a good article and I want to put it in context—what else has been tried? In other words, I don’t want to read 27 versions of the same thing. I want to get a broader sense of what’s out there.
The Narrow Search
The Trick: Find the PubMed entry for the article that you thought was so helpful, click on the author’s name, click “Review” under Article types on the left and then click on “related citations”
2. Where the first box says “All Fields,” use the drop-down menu to pick Author and type in “Wolchok.”
3. Hit return to give you a list of every article in PubMed in which someone named Wolchok is an author.
4. Click “review” under the “Article types on the left to filter your search so that you get only a list of review articles written by Wolchok.
5. Scan the list until you find the one that’s closest to your particular interest—say the one about “adverse events” in the Journal of the American Academy of Dermatology—and click the link for “related citations” that appears right under it.
6. Now you have a list of about 100 articles by various people researching different aspects of ipilimumab in patients with skin cancer—from a description of the whole class of drugs to which ipilimumab exists to an analysis of rare side effects.
7. Intriguingly, this search gives you different results from a simple search for “ipilimumab and melanoma” on PubMed, which returns about 500 articles—most of them apparently about side effects. That’s one reason I like to play around with different ways of searching to see how the results may vary.
A more advanced trick is to use the MESH terms—which stands for medical subject heading—embedded within any article to find a comprehensive but compact universe of similar citations. But that’s a subject for a future post.
I also plan to write a post in the coming weeks that compares searching PubMed to searching on popular search engine (Google, Bing, Yahoo. . .)
Have any tricks for using PubMed that you’d like to share? Let us know in the comments below.
Previous posts in The Quest series:
Or click on this tag: how-to-search-medical-info