This subject guide provides an overview of what a systematic review is and how Research Librarians can help researchers at the University of Tasmania during a systematic review process. This guide focuses on systematic reviews in a Health Sciences setting.
A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question. It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made (Antman 1992, Oxman 1993).
There are various types of literature reviews. This article describes fourteen different review types and associated methodologies (scroll down to Table 1 on p94/95):
These resources outline the difference between a systematic review and a literature review:
From Peters, MD, Godfrey, CM, Khalil, H, McInerney, P, Parker, D & Soares, CB 2015, 'Guidance for conducting systematic scoping reviews', International Journal of Evidence-Based Healthcare, vol. 13, no. 3, pp. 141-146:
"In general, scoping reviews are commonly used for ‘reconnaissance’ – to clarify working definitions and conceptual boundaries of a topic or field. Scoping reviews are therefore particularly useful when a body of literature has not yet been comprehensively reviewed, or exhibits a complex or heterogeneous nature not amenable to a more precise systematic review of the evidence. While scoping reviews may be conducted to determine the value and probable scope of a full systematic review, they may also be undertaken as exercises in and of themselves to summarize and disseminate research findings, to identify research gaps, and to make recommendations for the future research."
Many, but not all, systematic reviews contain meta-analyses. Meta-analysis is the use of statistical methods to summarise the results of independent studies. By combining information from all relevant studies, meta-analyses can provide more precise estimates of the effects of health care than those derived from the individual studies included within a review. Meta-analyses also facilitate investigations of the consistency of evidence across studies, and the exploration of differences across studies (Cochrane Handbook, 1.2.2).
More information on meta-analyses can be found in Cochrane Handbook, Chapter 9.
"Rapid reviews have emerged as a streamlined approach to synthesizing evidence in a timely manner -typically for the purpose of informing emergent decisions faced by decision makers in health care settings."
An umbrella review is a synthesis of existing reviews, only including the highest level of evidence such as systematic reviews and meta-analyses. It allows the findings of different reviews relevant to a review question to be compared and contrasted.
Methodology paper: Aromataris, E, Fernandez, R, Godfrey, CM, Holly, C, Khalil, H & Tungpunkom, P 2015, 'Summarizing systematic reviews: Methodological development, conduct and reporting of an umbrella review approach', Int J Evid Based Healthc, vol. 13, no. 3, pp. 132-140.