Skip to Main Content

Systematic Reviews, Scoping Reviews, and Health Technology Assessments - Searching the Literature

What Kind of Review

The following table contains a list of the most common types of reviews, the kinds of questions most suited to each, and examples of each.

Information on methods for different review types are found at Beyond Searching:  How do I do the rest of my review?

Choosing the Best Type of Review for Your Research Questsion

Type of Review When to use Definition Example
Narrative Review Narrative overviews are also known as unsystematic narrative reviews and are a comprehensive narrative synthesis of evidence. Typically, narrative reviews describe and appraise published articles although the methods for selection of articles may not be described. Consequently, narrative reviews are not usually reproducible. Narrative overviews may be as they synthesise information into a user-friendly format and present a broad perspective on a subject, its development and management. They can also offer practitioners up-to-date clinical protocols. These are the kinds of reviews most often done as background to a research project. They are not usually a research project on their own.  Narrative overviews may synthesise information into a user-friendly format and present a broad perspective on a subject, its development and management. They can also offer practitioners up-to-date clinical protocols. Epidemiology of eating disorders, eating disordered behaviour, and body image disturbance in males: a narrative review.
Scoping Review Scoping reviews are a rigorous research method designed to identify and map the available evidence. They are usually published as stand-alone articles. Scoping reviews are useful for examining emerging evidence when it is still unclear what other, more specific questions can be posed. They can report on the types of evidence that address and inform practice in the field and the way the research has been conducted.[1] Requires a research team and considerable time. Kleib M, Chauvette A, Furlong K, Nagle L, Slater L, McCloskey R. Approaches for defining and assessing nursing informatics competencies: a scoping review. JBI Evid Synth. 2021 Feb 19;19(4):794-841.
Systematic Review Systematic reviews follow a rigorous research method. They evaluate and summarise the findings of all relevant individual studies, and if appropriate, combine the results of several studies to provide more reliable results. Systematic reviews are usually published as stand-alone articles. Systematic reviews are the ‘gold standard’ of reviews because the review is based on explicit, prespecified and reproducible methods used to systematically search all sources of evidence and critically appraise, summarise and synthesise research findings to address a highly focused clinical question. Best used when a specific research question has been addressed by several studies and a pooling of the data from all of the studies will provide a stronger evidence base from which to make decisions. Requires a research team and considerable time. Symons, M., Pedruzzi, R.A., Bruce, K. et al. A systematic review of prevention interventions to reduce prenatal alcohol exposure and fetal alcohol spectrum disorder in indigenous communities. BMC Public Health 18, 1227 (2018).
Integrative Review Uses a non-experimental design, systematic approach and detailed search strategy to identify relevant evidence that answers a targeted clinical question. Researchers objectively critique, summarise and make inferences about a subject area and include thematic analysis of selected qualitative and quantitative research studies on the subject. Evidence can arise from a range of studies including randomised controlled trials (RCT), observational studies, qualitative research, clinical experts and any other relevant evidence in which the researchers objectively critique, summarise and make conclusions about a topic. They include systematic categorisation and thematic analysis of selected qualitative and quantitative research studies. Integrative review methodology is sophisticated and requires insight and adherence to detail. Most often used when there are numerous types of evidence sources addressing the question and the data is heterogeneous. An integrative review of facilitators and barriers influencing collaboration and teamwork between general practitioners and nurses working in general practice.
Rapid Review Summarises and synthesises research findings within the constraints of time and resources. The review needs to be as comprehensive as possible within the given constraints and undertaken in a systematic manner. Differs from a systematic review in relation to the extensiveness of the search strategies and methods used to undertake the analysis. However, the search should be comprehensive as possible and methods to evaluate and synthesise the evidence clearly outlined and rigorously applied. May fail to identify potentially relevant studies. Most often used when the literature of a field is changing quickly (e.g., Covid19) or when evidence is required for rapid decision making. Basically… porn is everywhere: a rapid evidence assessment on the effects that access and exposure to pornography has on children and young people.
Review of Reviews (Umbrella Review) A review of the literature, undertaken systematically, and sometimes referred to as an ‘umbrella review’. Compiles evidence from multiple research syntheses (usually systematic reviews) in order to summarise existing evidence and like systematic reviews follow clear methods. Useful when a review question is very broad and a number of systematic reviews have already been conducted in the topic area. However, the different inclusion criteria adopted by the reviews included can make interpretation problematic. A systematic review of reviews on the prevalence of anxiety disorders in adult populations.
Realist Review Focuses on understanding mechanisms by which an intervention works (or not). It involves identifying mechanisms that impact an intervention and exploring how they work and under what conditions. This review type includes defining the scope of the review with a clear aim: identifying relevant evidence; extracting and synthesising the evidence and explaining. Stakeholder involvement in the process is high as the realist review is derived following negotiation between stakeholders and reviewers Used when researchers want to develop and test theories that explain how complex contexts and conditions relate to interventions. Requires a research team and a great deal of time. Beneficial effects of ketogenic diets for cancer patients: a realist review with focus on evidence and confirmation.

[1]Munn, Z., Peters, M.D.J., Stern, C. et al. Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Med Res Methodol 18, 143 (2018).