Table 1

Key features of the common types of healthcare review

Type of reviewKey features
Systematic review6 Evaluates and summarises the findings of all relevant individual studies, and if appropriate, combines the results of several studies to provide more reliable results.
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.
Funded reviews typically involve a team of reviewers, and are often registered with a review centre such as the Cochrane Collaboration (, the Joanna Briggs Institute ( and the Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-Centre) ( and advisory support will be available.
Bariatric surgery: a systematic review and meta-analysis. 8
Rapid evidence assessment6 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.
Basically… porn is everywhere: a rapid evidence assessment on the effects that access and exposure to pornography has on children and young people. 9
Scoping review6 Identifies the size and nature of the evidence base for a particular topic area.
The literature search should be as extensive as possible, including a range of relevant databases, hand-searching and attempts to identify unpublished literature. Differs from a systematic review in that a synthesis of the literature is not usually undertaken.
Useful to map the literature in a broad context prior to undertaking a more comprehensive review. Helps identify the nature of the evidence particularly in an emerging health area, or to assess the feasibility of undertaking a full systematic review.
Not appropriate to answer a clinical question.
Patient and system factors of time to surgery after hip fracture: a scoping review. 10
Integrative11 reviewUses 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 evidence12 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.
An integrative review of facilitators and barriers influencing collaboration and teamwork between general practitioners and nurses working in general practice. 13
Realist review14 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.15
Beneficial effects of ketogenic diets for cancer patients: a realist review with focus on evidence and confirmation.
Narrative review17 18 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.
Epidemiology of eating disorders, eating disordered behaviour, and body image disturbance in males: a narrative review. 18
Review of reviews/umbrella review19 A review of the literature, undertaken systematically, and sometimes referred to as an ‘umbrella review’. Compiles evidence from multiple research syntheses 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. 20