A comprehensive literature review is essential for understanding and applying evidence-based medicine. This chapter seeks to equip the busy surgeon with a core set of techniques to efficiently retrieve and manage clinical information, and to interpret such data within the context of the greater body of surgical literature. More specifically, this chapter will provide (1) succinct database and search engine descriptions with advice for best search strategies, (2) a guide to two popular reference management applications, and (3) descriptions of tools for remaining current with the latest clinical research. To understand the importance of the literature search, the chapter begins with some relevant clinical scenarios.

Scenario 1

A 42-year-old male is admitted to the intensive care unit with refractory septic shock secondary to perforated peptic ulcer. Treatment consists of antibiotics, intravenous fluid support, and norepinephrine. The intensivist wants to know whether evidence exists to support the addition of vasopressin, and asks you to locate articles on the topic, in particular articles that have significantly impacted clinical practice.

Locate High-Impact/Seminal Articles: One quick-and-easy method for identifying high-impact articles in a particular clinical domain is to rank papers by “times cited,” which is simply the number of times that an article was cited in other works (typically, other journal articles). Two tools for determining times cited are Google Scholar (free) and SCOPUS (subscription-only). Google Scholar ranks its results using a relevance weighting algorithm that, among other things, adds greater relevance to a search result that is frequently cited. SCOPUS, on the other hand, allows searchers to simply sort results from most to least cited (or vice versa).

Other tools such as Faculty of 1000 and NEJM Journal Watch use an actual cadre of subject experts rather than algorithms to identify noteworthy articles. However, both of these are subscription services.

Searching Google Scholar: As the name implies, Google Scholar is a resource for locating scholarly information, including academic articles, patents, books, court opinions, and theses. One of the key benefits of Google Scholar is the ability to search the full text of an item, not just the titles, abstracts, and supplemental keywords found in traditional literature databases such as PubMed, SCOPUS, and Web of Science. Search terms that might not appear in a standard reference (eg, an obscure lab method, a psychometric test, a health statistic) are potentially discoverable in the full text.

As mentioned previously, the number of times that an article is cited plays a significant role in ranking search results. Searchers can also view who is citing the work by clicking on the “Cited by” link.

Despite its utility, citation count as an indicator of relevance is imperfect. Inherent delays in reading and citing a particular work diminish the efficacy of citation count in detecting new articles that might become seminal.¹ Also, an article may be cited frequently because of the controversy—positive or negative—that it generates, rather than its relevance to standard of care.

Let’s return to our scenario. We’ll start our research into vasopressin, norepinephrine, and septic shock with a search of Google Scholar. Our intent is to quickly identify some key articles on the topic using the ranking algorithm.

Google Scholar Search Results: A seminal work by JA Russell on vasopressin and norepinephrine in septic shock is the first reference listed.

Google Scholar Search Tools and Techniques

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  Search Operators: To exclude terms from a search, use the minus (–) symbol, for example, “skull base surgery” –cadaver. Use quotes to search an exact phrase, such as “postpartum hemorrhage.”

  
  
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  Downloading: Google Scholar has a “Settings” icon on the initial page that will allow you to activate an “Import to EndNote” link on your search results. Unfortunately, only one reference at a time can be imported from Scholar to EndNote. Zotero, a free citation management tool, provides an option for downloading all the results of a page with one click. Both of these reference management tools are discussed in more detail below.

Searching SCOPUS: SCOPUS is a subscription-based, multidisciplinary database covering topics ranging from astronomy to urology and virtually everything in between. In addition to supplying a huge database of article references, SCOPUS provides citation counts, researcher profiling tools (including H-Index scores), and metrics for evaluating an article’s impact.

Now, let’s search SCOPUS to locate any article on vasopressin and norepinephrine for treating septic shock and sort by citation count. For more information on the impact of the article, scan the SCOPUS “Metrics” report.

SCOPUS Search Results: The screenshot above shows the results of a title/abstract/keyword search of vasopressin AND norepinephrine AND “septic shock” sorted by citation count (most to least cited). Click the title of citation 4 to retrieve the Metrics report on the Dellinger article.

Note how Metrics tracks “the buzz” on an article via numerous social media tools and resources, such as Twitter, Facebook, Wikipedia, blogs, and Mendeley (a web tool for sharing research papers).

SCOPUS Search Tools and Techniques: SCOPUS uses the standard array of literature database search options:” Boolean operators AND, OR, and NOT; the asterisk * as a wild card; and double quotes for phrase searching. Searchers use pulldown menus to choose which fields within a reference to search.

Returning to the scenario, suppose that the intensivist wants to find out about any new articles that come up on this topic. There are multiple ways to stay current on the literature. Two of these strategies are BrowZine and Faculty of 1000.

Keeping Current with BrowZine: BrowZine is a service that allows you to browse and read articles from your favorite academic journals. If your institution subscribes to BrowZine, you can install the mobile application and use it to select and add specific journals to your own personalized digital library collection. Similar to an actual library reading room, BrowZine populates “shelves” with digital journals. New, unread articles are indicated by a number overlaying the image of the journal’s cover. Alerts to new journal issues are sent as notifications to your device. BrowZine is currently available as an application for tablets and smartphones using either the Apple iOS or Android OS. BrowZine can also be used without subscription to access a much smaller collection of open-access journals.

The first screenshot of BrowZine shows surgery journal subcategories; the second screenshot shows final journal selection.

The third screenshot shows the table of contents for an issue of Archives of Surgery.

Keeping Current with Faculty of 1000 (F1000)—Prime: F1000 is a subscription-based service that provides article recommendations from thousands of world-renowned researchers in the clinical and life sciences. The topics and specialties in F1000 are often quite focused: pediatric anesthesiology, dermatologic and cosmetic surgery, and so on. In addition to providing options for creating autoalerts, F1000 can also be searched as a standalone database.

Search for recommendations on articles relating to “septic shock” in the following screenshot:

F1000 Search Results: Results include commentary and an overall “score” based on reviewer recommendations.

Additional Tools for Keeping up with the Latest Clinical Research: AutoAlerts, Recommendation Services, eTOCS, and More

Database Autoalerts: Most literature databases (eg, PubMed) and search engines provide utilities for building “autoalerts.” Create an account in the database, run and save a search, and indicate how often alerts should be delivered.

Google Scholar Autoalerts: Access via http://scholar.google.com. Create a Google account. Run a search, then click on the “Create Alert” icon and follow the prompts.

Electronic Tables of Contents (eTOCS): A very popular method for receiving an email with the most recent issues of a journal, eTOCS are becoming increasingly available for most peer-reviewed journals. Signing up is usually a matter of visiting the journal’s website, creating an account, locating an alert link (usually labeled “Alerts” or “eTOCS”), and activating the alert. The emails typically contain an attractively formatted list of articles from the latest issue of the journal, with embedded links to the full text.

READ (BY QXMD): READ is one of many customizable medical journal readers. Users select journals to follow, view article suggestions by specialty, or scan article collections created by other QxMD users. Available for Android and iOS and via a web browser. (Website: http://www.qxmd.com/apps/read-by-qxmd-app)

Scenario 2

Impressed by your ability to identify key articles on septic shock, norepinephrine, and vasopressin, the surgery attending asks you to give a presentation on the topic at next month’s journal club. In preparation for the talk, you decide to design and run a well-constructed search on the topic in PubMed.