If you're in the research field, there's a good chance you'll need to write a systematic review at some point in your career. However, if you're new to the process, you may be wondering where to begin. In this article, we'll take a comprehensive look at what a systematic review is and how to write one step-by-step.
Understanding Systematic Reviews
Before we dive into the nitty-gritty of writing a systematic review, it's essential to understand what they are and why they matter.
Systematic reviews are a type of research study that involves collecting and analyzing all available evidence related to a particular research question. These reviews are structured and transparent and follow pre-determined inclusion and exclusion criteria to minimize bias and ensure that the evidence is current, relevant, and reliable.
Systematic reviews are an important tool in evidence-based research and are used to inform clinical decision-making, health policy, and future research. By synthesizing all available evidence related to a particular topic, systematic reviews provide a comprehensive overview of the current research landscape, help identify gaps in knowledge, and inform future research.
What is a Systematic Review?
A systematic review is a comprehensive study that pulls together all available evidence related to a particular research question. This type of review involves a rigorous and transparent process that includes a comprehensive search of the literature, a critical appraisal of the quality of the evidence, and a synthesis of the findings.
Systematic reviews are often used to answer complex research questions or to provide a summary of the current state of knowledge on a particular topic. These reviews can be used to inform clinical practice, health policy, and future research.
Importance of Systematic Reviews in Research
Systematic reviews are a critical component of evidence-based research and are used to inform clinical decision-making, health policy, and future research. By synthesizing all available evidence related to a particular topic, systematic reviews provide a comprehensive overview of the current research landscape, help identify gaps in knowledge, and inform future research.
Systematic reviews are particularly important in fields such as medicine, where decisions about patient care are often based on the best available evidence. By providing a comprehensive and unbiased summary of the available evidence, systematic reviews can help clinicians make informed decisions about patient care.
Differences Between Systematic Reviews and Other Review Types
It's essential to understand the differences between systematic reviews and other types of reviews to determine which approach is most appropriate for your research.
A scoping review is a type of review that aims to map the available evidence on a particular topic, identify gaps in knowledge, and highlight areas for future research. Scoping reviews are often used to provide an overview of the literature on a particular topic and can help researchers identify areas where further research is needed.
A narrative review is a type of review that aims to provide an overview of the literature related to a particular topic. These reviews are often subjective and may include personal opinions. Narrative reviews are useful for providing a broad overview of a topic, but they may not be as rigorous or transparent as systematic reviews.
In contrast, a systematic review follows a structured and transparent process and adheres to pre-determined inclusion and exclusion criteria to minimize bias and ensure that the evidence is current, relevant, and reliable. Systematic reviews are considered the gold standard in evidence-based research and are often used to inform clinical practice and health policy.
Preparing for Your Systematic Review
Now that we've covered the basics of what a systematic review is let's dive into how to prepare for writing one.
Defining Your Research Question
The first step in writing a systematic review is to define your research question. Your research question should be clear, focused, and answerable through the available literature.
Some tips for formulating your research question include:
- Be specific and clear
- Use appropriate search terms
- Consider the scope of your review (e.g., what studies are included)
- Consider the purpose of your review (e.g., is a systematic review necessary, or would a scoping review suffice?)
Developing a Protocol
A protocol is a well-defined plan that outlines your systematic review's objectives, methods, and eligibility criteria. Having a protocol in place before beginning your review helps ensure that the process is transparent, systematic, and reproducible.
Your review protocol should outline the following:
- Research question(s)
- Inclusion and exclusion criteria
- Search strategy
- Data extraction and synthesis methods
Assembling Your Review Team
Systematic reviews are a significant undertaking that can take months or even years to complete. As such, it's crucial to assemble a reliable review team to ensure that the process is efficient, transparent, and thorough.
Your review team should include:
- Content experts
- Methodologists (e.g., statisticians, information specialists)
- Reviewers (who will conduct the review)
- Project manager/leader
Conducting a Comprehensive Literature Search
Now that you have your research question and review protocol in place let's move on to conducting a comprehensive literature search.
Identifying Relevant Databases and Resources
To conduct a comprehensive literature search, you must identify relevant databases and resources. These may include:
- PubMed
- Google Scholar
- EMBASE
- The Cochrane Library
You should also consider searching for grey literature (i.e., unpublished studies or studies that appear in conference proceedings).
Developing a Search Strategy
Once you've identified your relevant databases and resources, the next step is to develop a search strategy. Your search strategy should be designed to retrieve all relevant studies while minimizing irrelevant studies included in your review.
Your search strategy should include:
- Search terms (including synonyms and related terms)
- Search filters (e.g., language, study type)
- Boolean operators (e.g., AND, OR)
Managing and Organizing Your Search Results
Conducting a comprehensive literature search can generate hundreds or even thousands of search results. Therefore, it's crucial to manage and organize your search results efficiently.
You can use reference management software such as EndNote or Mendeley to manage your search results. You should also create a screening form to record key information about each study.
Selecting and Screening Studies for Inclusion
Now that you have your search results, it's time to start selecting and screening studies for inclusion in your review.
Establishing Inclusion and Exclusion Criteria
Before beginning the screening process, it's important to establish inclusion and exclusion criteria. These criteria should be based on your research question and review protocol and should be transparent and reproducible.
Screening Titles and Abstracts
Screening titles and abstracts is the first step in the inclusion/exclusion process. You should screen each title and abstract to determine whether the study meets your pre-determined inclusion/exclusion criteria.
Assessing Full-Text Articles
Once you've screened the titles and abstracts, you'll need to assess the full-text articles of studies that meet your inclusion criteria.
You should extract data on study design, population, intervention/exposure, outcomes, and study quality. You can use data extraction forms to standardize this process.
Assessing study quality is also an important aspect of the review process. There are several tools available for assessing study quality, including the Cochrane Risk of Bias Tool and the Joanna Briggs Institute Critical Appraisal Checklist.
