Systematic reviews seek to gather all the available evidence that fits pre-specified eligibility criteria to answer a specific research question. They aim to minimize bias by using explicit, systematic methods documented in advance with a protocol. A Meta-Analysis is the statistical combination of two or more separate studies which yields an overall statistic, and is one of the synthesis approaches that can be used for systematic reviews.
Systematic reviews take time, typically 6-18 months to complete. They require a team of researchers with expertise in the pertinent clinical topic areas, systematic review methods, searching for relevant evidence, quantitative methods, and other areas as appropriate. Teams should consider incorporating key users and stakeholders to guide the development of the review.
Why conduct a systematic review?
A systematic review might be conducted for any the following reasons:
- Identify and investigate conflicting results from primary research
- Confirm current practice while addressing variations and identifying new practices
- Identify and inform areas for future research
- Produce statements to guide decision-making
Before conducting a systematic review, you should first consider whether a systematic review is the correct methodology to address your research question. Use the decision tree below to confirm review type.
Alternative Methods
Alternative Methods
Scoping Review
- If you determine that a scoping review is the appropriate methodology, please see Chapter 10 of the JBI Manual for Evidence Synthesis. A knowledge base article on scoping reviews will soon be published on the Library's website.
Narrative Review
- If you determine that a narrative review is the best method, a knowledge base article on scoping reviews will soon be published on the Library's website.
Umbrella Review
- For more information about umbrella reviews, please see Chapter 9 of the JBI Manual for Evidence Synthesis.
Integrative Review
- For more information about integrative reviews, please see the methodology paper by Whittemore and Knafl published in 2005.
Rapid Reviews
- Lastly, for more information about rapid reviews, please see the guidance provide by the Cochrane Rapid Reviews Methods Group.
How to conduct a systematic review?
Below you'll find the critical resources, standards, and steps for systematic reviews.
Handbooks
Systematic reviews adhere to a rigorous set of steps. You should consult one of the following Handbooks for step-by-step guidance on the conceptualization, procedures, and conduct of your systematic review.
Cochrane Handbook JBI Manual for Evidence Synthesis
Institute of Medicine's Standards for Systematic Reviews
To help you determine which handbook is most appropriate, please review the table below:
| Characteristics | Cochrane Handbook | JBI Manual | IOM Standards |
|---|---|---|---|
| Type of Systematic Review | Effectiveness of clinical interventions | All types, including social sciences | Effectiveness of clinical and non-clinical interventions |
| Types of Evidence | Experimental, observational | Experimental, observational, cross-sectional, qualitative, mixed methods | Experimental, observational |
| Strength | Detailed methodologies for RCTs and controlled trials, including meta-analysis and assessment of bias | Flexible; can accommodate reviews with a broad scope and a mix of evidence types | A rigorous approach to assessing the quality of evidence |
| Publication Year | 2023 | 2024 | 2011 |
| Example Review Title | Assessing the efficacy of a new antidepressant medication compared to an existing drug in the treatment of adolescents with depression. | Assessing the burden of chronic illness on patient self-reported quality of life, incorporating both quantitative survey data and qualitative interviews. | Assessing the efficacy of a new proton pump inhibitor compared to standard care for patients with gastroesophageal reflux disease. |
Reporting standards
Systematic reviews should also adhere to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The PRISMA 2020 Checklist ensures that all information that should be reported in a systematic review is reported in the final manuscript. Click here to access PRISMA for the 2020 Checklist, 2020 Flow Diagram, and other reporting checklists like PRISMA for Protocols, PRISMA for Abstracts, and PRISMA Search.
General steps of a systematic review
The handbook you have selected will provide detailed instructions of the steps required to conduct a systematic review:
1. Define the question
The first step is to select and define your question. At this stage, you should also be planning the logistics of your review, such as:
- members of the review team;
- resources that are available to you;
- estimated timeframe;
- any conflict of interest.
2. Plan the review
- Next, plan the criteria you are going to use to decide whether a piece of research is eligible for inclusion in your review.
- Also plan which methods you will use to conduct the review.
3. Publish the protocol
- A published protocol is good practice for any piece of research. Protocols for systematic reviews can be registered with the PROSPERO register of systematic review protocols.
4. Conduct the review
Only after the protocol is finalized do you proceed with the review:
- running a systematic search to identify all the included studies;
- applying eligibility criteria;
- collecting information from each included study;
- assessing each study for bias;
- analyzing and interpreting the results.
We highly recommend that you utilize the information and instructions provided in our Preliminary Topic Investigation article to supplement the information provided in your chosen handbook.
Further training
If you are interested in training for systematic reviews, please consider the following resources:
A series of self-directed learning modules from Cochrane that provides in-depth training for systematic reviews. Download a certificate after the completion of each module. Requires a Columbia UNI to access.
A playlist of video trainings from the JBI on systematic review methods.
Educational classes and programs on a variety of topics, including systematic reviews. Attend live classes or watch recordings of previous programs. Recordings require a Columbia UNI to access.
Further reading
- Munn, Z., Peters, M. D. J., Stern, C., Tufanaru, C., McArthur, A., & Aromataris, E. (2018). Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC medical research methodology, 18(1), 143. https://doi.org/10.1186/s12874-018-0611-x