By: Annie Wescott, Research Librarian

The systematic review sits atop the evidence based medicine pyramid and is held in high regard in the research community. While a systematic review aims to reduce bias and synthesize evidence, it may not always the best choice for every research question. Whether you are struggling to focus your review question or you are concerned about the time commitment necessary for a systematic review, you may wish to consider other review types that better suit your needs.

A scoping review can be a standalone review that employs systematic methods or an examination of the literature in preparation for a systematic review. The goal of a scoping review is to assess the scope of a research topic. While a systematic review may ask a specific question, a scoping review can be used to examine a broader research topic. Consider stepping back and looking at the full scope of the literature on your topic if you find yourself struggling to focus your research to a specific question. Note: a scoping review may take as long or longer than a systematic review.

A mapping review is an excellent option for categorizing the landscape of a research topic and identifying any possible gaps in the literature on a given area. A mapping review may be a good place to start if you find yourself asking a number of questions about a single topic. Similar to a scoping review, a mapping review takes in the scope of the literature and organizes it in order to make sense of the broader conversation.

The literature or narrative review is often the first type of review that comes to mind. This review has the most relaxed structure, allowing the author freedom to decide their level of comprehension and synthesis. A literature review is typically narrative in structure and may summarize a topic or cover a range of subjects as it relates to a research question.

Are there already a number of reviews on your topic of interest? An umbrella review is a good option when you would like to take a high-level view of the review literature on a research topic and synthesize the information from other reviews. The methods remain similar to the systematic review process, but you are no longer looking for primary research. Instead, you are focusing on identifying what is known and unknown across the review literature on your topic.

A systematized review allows authors to truncate the systematic review process. This is a great option for those who want to get the feel and structure of a systematic review, but who may not have the time to commit to the process, the necessary team members, or encounter other limitations to the typical systematic review methodology. A systematized review may be a better option for student assignments when the goal is to get a feel for the process without the full commitment to a protracted review process.

A critical review takes a step back from the full scope of the literature on a given topic to focus on the most significant contributions to the research discussion. An author may take a more narrative approach when synthesizing the literature on the topic but would still seek to gather an in-depth understanding of the research question.

Chart adapted from: Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Info Libr J. 2009 Jun;26(2):91-108. doi: 10.1111/j.1471-1842.2009.00848.x.