Users' guide to the surgical literature: how to use a systematic literature review and meta-analysis

Readers are able to utilize several types of summarized information from expert opinion and textbook reviews to systematic reviews. Traditional, or narrative, reviews, by definition, do not use a systematic approach to identifying information on a particular topic. Moreover, narrative reviews often pose background-type questions and provide a general overview of a topic such as those found in book chapters and instructional course lectures. A background question is, for example, "What is the epidemiology, clinical presentation, treatment options and prognosis following femoral shaft fractures in adults?" We use the term systematic review for any summary of the medical literature that attempts to address a focused clinical question with explicit strategies for the identification and appraisal of the available literature (Table 1 and Table 2); meta-analysis is a term used for systematic reviews that use quantitative methods (i.e., statistical techniques) to summarize the results. Systematic reviews typically pose a foreground-type question. Foreground questions are more specific and provide insight into a particular aspect of management. For instance, investigators may provide a systematic review of plating versus nailing of humeral shaft fractures on nonunion rates (foreground question) rather than a general review of how bone heals after all treatments of humeral shaft fractures (background question). You quickly determine from talking with your colleagues and your fellowship supervisor that there have been a number of randomized trials comparing operative and nonoperative treatment of acute ruptures of the Achilles tendon. Realizing that your 1-week deadline will not be sufficient to summarize all of the articles, you decide to focus your literature search to identify any recent reviews of this topic. Being relatively proficient on the Internet, you select your favourite search site, National Library of Medicine's PubMed at www.pubmed.gov. You select the "Clinical Queries" section and choose a search for systematic reviews. You type in the words "Achilles tendon." This identifies 12 documents. You review the titles of the 12 potentially relevant studies and are happy to find a systematic review and meta-analysis of operative versus nonoperative treatment for acute ruptures of the Achilles tendon.3 You retrieve this article for further review. The meta-analysis of operative versus nonoperative treatment of Achilles tendon ruptures meets most of the criteri