Systematic reviews seek to collate all evidence that fits pre-specified eligibility criteria in order to address a specific research question. They aim to minimize bias by using explicit, systematic methods. (from Cochrane Handbook for Systematic Reviews of Interventions)
A systematic review is a review that reports or includes the following:
i) research question
ii) sources that were searched, with a reproducible search strategy (naming of databases, naming of search platforms/engines, search date and complete search strategy)
iii) inclusion and exclusion criteria
iv) selection (screening) methods
v) critically appraises and reports the quality/risk of bias of the included studies
vi) information about data analysis and synthesis that allows the reproducibility of the results
(from Krnic Martinic, M., Pieper, D., Glatt, A. et al. Definition of a systematic review used in overviews of systematic reviews, meta-epidemiological studies and textbooks. BMC Med Res Methodol 19, 203 (2019) doi:10.1186/s12874-019-0855-0)
Systematic Reviews should address a clearly formulated, relatively narrowly focused question and use systematic and explicit methods to identify, select, and assess relevant research.
Before you embark on a systematic review, please understand that this could easily be a one year or more project. Here is a decision tree (source) to help you decide is a systematic, or other type or review, is appropriate. The SPARK Tool to prioritise questions for systematic reviews in health policy and systems research can help you decide if a systematic review is appropriate and needed. If you do decide to conduct a systematic review, please register your protocol.
PRISMA for searching: 16 item checklist to ensure your systematic review database searching complies with standards.
You may wish to consider conducting another type of literature review; see this table for information on several types of reviews (eg, scoping review, mapping review, rapid review, etc.). (Table reproduced from A typology of reviews: an analysis of 14 review types and associated methodologies).
These articles may also be helpful:
How to conduct a systematic review from beginning to end (from Covidence; easy to read summary of the 7 steps).
Five steps to conducting a systematic review. Khan KS, Kunz R, Kleijnen J, Antes G. Journal of the Royal Society of Medicine. 2003 Mar;96(3):118-21.
A Guide to Conducting a Standalone Systematic Literature Review. Okoli C. Communications of the Association for Information Systems 2015; 37(1): 879-910.
Incorporating Judgments about Study Quality into Research Syntheses. (pdf). Valentine JC. Chapter 7 of Cooper, Harris, Hedges, Larry V., Valentine, Jeffrey C. The Handbook of Research Synthesis and Meta-Analysis. New York : Russell Sage Foundation, 2019.
Excellent review of what to consider, and what not to consider, when judging study quality.
Performing Rapid Reviews. King VJ et al. Systematic Reviews 2022; 11:151.
Highly recommended if you are considering performing a rapid review.
Rapid Review Guidebook. Rapid reviews differ from systematic reviews in that the process is tailored for a shorter timeline, but it is still important to use rigorous methodology to ensure that the best available research evidence is used in decision making. The National Collaborating Centre of Methods and Tools (Canada) has developed a Rapid Review Guidebook that details each step in the process. It also includes information on how to structure the written report, and what to include in each section.
The difference between a systematic review and a scoping review (from Covidence).
Systematic vs Scoping Review: What's the Difference? (5 minute video, Carrie Price, Health Professions Librarian, Towson University).
PRISMA for Scoping Reviews. Includes a checklist with 20 essential reporting items and 2 optional items to include when completing a scoping review, as well as one-page tip sheets on each item.
Recommendations for the extraction, analysis, and presentation of results in scoping reviews. Pollock D et al. JBI Evidence Synthesis. 2022 Sep 8.
Recommended reading if you are considering conducting a scoping review.
Guidance to best tools and practices for systematic reviews. "Exemplar methods and research practices are described, complemented by novel pragmatic strategies to improve evidence syntheses." British Journal of Pharmacology, 1–31, 2023.
If you are faced with a large number of abstracts to screen, see Best practice guidelines for abstract screening large-evidence systematic reviews and meta-analyses; Res Syn Meth. 2019; 10: 330–342. https://doi.org/10.1002/jrsm.1354.
An article on the importance of looking at the science behind the articles you review when assessing quality: Challenges and recommendations on the conduct of systematic reviews of observational epidemiologic studies in environmental and occupational health Arroyave WD, et al. Journal of exposure science & environmental epidemiology 2021; 31(1):21-30.
Consult the Cochrane Handbook for Systematic Reviews of Interventions (2nd edition) for a very thorough discussion of the systematic review process.
The UC Berkeley Library licenses Covidence, a tool to help you with your systematic reviews.
In Covidence, you can:
As an institutional member, our users have priority access to Covidence support. Our license allows unlimited simultaneous reviews, and you can add people who are not affiliated with UCB.
To access Covidence using the UC Berkeley institutional account, start at this page and follow the instructions. Many tutorials, help pages, webinar recordings, and more may be found in the Covidence Knowledge Base;
Other systematic review tools besides Covidence include PICO Portal, Rayyan, Sysrev, and more.
How long will it take to complete a systematic review? Use the PredicTER tool to find out!
And, some thoughts on assigning systematic reviews as course assignments: Is there better teaching opportunity than assigning systematic reviews in a semester?