Systematic Reviews and Meta-Analyses

Systematic reviews and meta-analyses have long been considered one of the highest levels of evidence, and lately, publication frequency in health science journals is on the rise.  However, there are still a lot of people who are unaware of what goes into writing a systematic review or a meta-analysis. This post will discuss what a systematic review entails, how it differs from a meta-analysis, and the value that librarians bring to both types of studies.

A systematic review is a research study that seeks to find all the high quality studies done on a given topic so that they can be summarized into one article.  If the studies are homogenous or similar enough to one another, the data can be extracted and combined using statistical formulas. This statistical compilation of data is a meta-analysis. Not all systematic reviews contain a meta-analysis, but all citations to be included in a meta-analysis should be located through a systematic search, to reduce the risk of bias.

An important part of preparing a systematic review is to ensure that the method used is explicit and transparent, allowing for another team to replicate the process. The first step involves putting together a team of at least two researchers who will independently review the studies located.  These researchers then develop a research question and write up a protocol that explicitly detailing how the systematic review will be carried out. One of the details is the criteria against which studies will be assessed for inclusion in the review. It is highly recommended that researchers register their protocols before they begin the formal search for studies.  Once the protocol is in place, the search for and review of high quality studies can begin. Systematic reviews can take anywhere from one year to eighteen months to complete due to the rigorous nature of the review process. Librarians are highly skilled and trained to develop what are often complicated and lengthy search strategies in order to locate as many relevant studies as possible.  They are also familiar with standards and basic steps for completing a systematic review. In the report, Finding What Works in Health Care: Standards for Systematic Reviews, the Institute of Medicine recommends working with a librarian or other information specialist to plan out the search strategy and to peer review the final strategy used to locate studies. Three of the librarians are Hardin Library have attended the Systematic Review Workshop: The Nuts and Bolts for Librarians which takes place over the course of two and a half days.

If you would like to learn more about conducting and locating systematic reviews, please see the Systematic Review LibGuide. You are also welcome to contact us if you have any questions.

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