Traditionally, systematic reviews are considered as the gold standard to inform clinical practice and policy decisions. However, systematic reviews are resource and time intensive. The time factor has been identified as a barrier to implementing results from evidence synthesis, as a result of an incongruence between the time required to produce a full systematic review and the time within which policy and other decision makers must take decisions.1,2 Hence, there is an increasing demand and a rising interest from healthcare decision makers and knowledge users for a summary of high-quality evidence within a short time period to support their practice and policy decision-making.1,3
Rapid reviews are viewed as valid forms of evidence synthesis products that provide sufficient information and advice to base clinical and policy decisions.3 A rapid review enables the provision of a concise summary of the evidence to answer specific policy or research-related questions. This recent interest in RRs could be due to the relatively large resource, time, and budget demands of well conducted systematic reviews.
The term ‘rapid review’ (RR) has broad and varied definitions, and it is important to know how it differs from a systematic review. Broadly, a rapid review is a type of evidence synthesis product, which includes components of a systematic review, albeit in a simplified form that enables it’s completion in a timely fashion.3,4
A rapid review differs from a systematic review in terms of the scope of the review question, comprehensiveness of the search, rigour and/or quality control, and the type of synthesis.3,4,5 Overall, a RR is similar to a systematic review in terms of how the evidence is identified, appraised, selected and synthesised. However, to enable the review to be completed within a short timeframe, certain steps in the systematic review process are altered or skipped or modified or omitted!
In order to achieve best possible outcomes to facilitate the use of RRs in decision-making and overcome the barriers of lack of timely and relevant research, a range of methods have been developed, which involve modifications to the systematic review methods.1,5,6,7 According to Khangura et al (2012), limiting the scope of RRs or having a more targeted research question is probably the most efficient shortcut because of its impact on the number of articles, including full-texts to be retrieved, screened, assessed and synthesised (including data extraction).5 However, the authors do state that it is important to engage and collaborate closely with the knowledge end-users.1,5,8 Other modifications to the traditional systematic review method include: a reduced list of sources or databases to be searched, including limiting these to specialised sources (e.g. of systematic reviews), or by date, or by language; exclusion of grey literature; relying on existing systematic reviews; full-text review limitation; the use of only one reviewer for study selection and data extraction; providing minimal conclusions or recommendations; and limiting external peer review.1,5,8
Currently, there is no formal established methodological guidance on conducting and reporting RRs, and there is some recent work that identified a variety of approaches to RRs.4 A project work related to the extension of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines (for systematic reviews) for the conduct and reporting of RRs is currently underway and registered with the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) Network.9
In a scoping review of RRs that compared the results of RRs to full systematic reviews (SRs) in four studies, it was found that the results reported in both the types of reviews were similar, with no incongruence.4 A rapid review in collaboration with clinical experts and/or knowledge end-users is thus a useful tool for assisting clinicians and policy decision-makers to identify evidence-based strategies for implementation into practice and to identify future research priorities.
- Khangura S, Polisena J, Clifford TJ, Farrah K, Kamel C. Rapid review: an emerging approach to evidence synthesis in health technology assessment. Int J Technol Assess Health Care. 2014; 30(1):20-7.
- Featherstone RM, Dryden DM, Foisy M, Guise JM, Mitchell MD, Paynter RA, et al. Advancing knowledge of rapid reviews: an analysis of results, conclusions and recommendations from published review articles examining rapid reviews. Systems Review. 2015; 4(50).
- Munn Z, Lockwood C, Moola S. The Development and Use of Evidence Summaries for Point of Care Information Systems: A Streamlined Rapid Review Approach. Worldviews Evid Based Nurs. 2015 Jun; 12(3):131-8.
- Tricco AC, Antony J, Zarin W, Strifler L, Ghassemi M, Ivory J, et al. A scoping review of rapid review methods. BMC Medicine. 2015; 13(224).
- Khangura S, Konnyu K, Cushman R, Grimshaw J, Moher D. Evidence summaries: the evolution of a rapid review approach. Systems Review. 2012; 1(10).
- Polisena J, Garrity C, Kamel C, Stevens A, Abou-Setta AM. Rapid review programs to support health care and policy decision making: a descriptive analysis of processes and methods. Syst Rev. 2015; 4:26.
- Ganann R, Ciliska D, Thomas H. Expediting systematic reviews: methods and implications of rapid reviews. Implement Sci. 2010; 5:56.
- Haby MM, Chapman E, Clark R, Barreto J, Reveiz L, Lavis JN. What are the best methodologies for rapid reviews of the research evidence for evidence-informed decision making in health policy and practice: a rapid review. Health Res Policy Syst. 2016; 14: 83.
- The EQUATOR network 2015, PRISMA-RR 2017: an extension to PRISMA for rapid reviews, Enhancing the QUAlity and Transparency Of health Research (EQUATOR) Network, Centre for Statistics in Medicine, NDORMS, University of Oxford, London.
Written By – Dr. Sandeep Moola (Research Fellow, The University of Adelaide, Australia)