Systematic and scoping reviews: A comparison and overview

In this article, we compare and contrast methods of reviewing, summarizing, and synthesizing the literature, including systematic reviews, scoping reviews, and narrative reviews. Review articles are essential to help investigators wade through the plethora of exponentially growing medical literature. In the era of evidence-based medicine, a systematic approach is required. A systematic review is a formalized method to address a specific clinical question by analyzing the breadth of published literature while minimizing bias. Systematic reviews are designed to answer narrow clinical questions in the PICO (population, intervention, comparison, and outcome) format. Alternatively, scoping reviews use a similar systematic approach to a literature search in order to determine the breadth and depth of knowledge on a topic; to clarify definitions, concepts, and themes; or sometimes as a precursor to a systematic review or hypothesis generator to guide future research. However, scoping reviews are less constrained by a priori decisions about which interventions, controls, and outcomes may be of interest. Traditional narrative reviews still have a role in informing practice and guiding research, particularly when there is a paucity of high-quality evidence on a topic.