Systematic reviews are a type of literature review in which authors systematically search for, critically appraise, and synthesize evidence from several studies on the same topic (Grant & Booth, 2009). The precise and systematic method differentiates systematic reviews from traditional reviews (Khan, Kunz, Kleijnen, & Antes, 2003). In all types of systematic reviews, a quality assessment is done of the individual studies that meet inclusion criteria. These individual assessments are synthesized, and aggregated results are reported. Systematic reviews are considered the highest level of evidence in evidence-based health care because the reviewers strive to use transparent, rigorous methods that minimize bias.
Milner, Kerry A. "Systematic Reviews." Oncology Nursing Forum 42.1 (2015): 89-93.