Systematic reviews have gained popularity over the years and are different from other literature reviews that exist in academic research. These reviews provide a thorough analysis of existing research to understand how conclusions are made and to answer the research question at hand. This detailed assessment aids in comprehending the logical flow of research, the methodologies applied, and the applications used.
However, to complete a systematic review efficiently and effectively, a well-defined roadmap is necessary that defines the process and guidelines to be followed, which is known as a systematic review protocol. In this blog, learn what is protocol for systematic literature review, what are its key characteristics and a step-by-step guide to writing a protocol for systematic review.
What is A Systematic Review Protocol
To understand the research protocol for systematic review, it is crucial to first gain knowledge about the meaning of a systematic review protocol. A systematic review protocol serves as a blueprint for your research and contains detailed information on every stage of the review process such as the rationale, the aims and objectives, the hypothesis and the methods to be used.
Apart from this, it also encompasses the following elements:
- Selection of team members
- Search Terms
- Databases
- Methodologies & Strategies
- Inclusion/Exclusion criteria
- Timeline
- Target Journals and Studies
- Quality Assessment Tool
- Data Analysis Plan
Characteristics Of A Systematic Review Protocol
Developing a systematic review protocol is the second most important part of the review process after the formulation of the research question. This protocol should be defined before the process of the review starts, used to guide it and be made public so that transparency is ensured. There are many reporting standards that set guidelines for establishing a protocol however, they vary from journal to journal. Additionally, there are certain features or characteristics of a systematic review protocol, such as:
- A systematic review protocol is strictly pre-defined, unlike other reviews.
- A suitable protocol for a systematic literature review is transparent about the methods used.
- It allows other reviewers and researchers to understand the roadmap of your research and summaries your outcome data.
- Its structure is rigid and less flexible.
- A systematic review protocol maps areas of uncertainty and addresses gaps for new research.
Importance Of Protocol For A Systematic Review
A review protocol for a systematic review can change from time to time as the review process progresses. A researcher can add or subtract elements as needed to suit the research objectives. However, it is good to familiarise yourself with the importance of establishing a protocol while conducting a systematic review:
- A well-defined systematic review protocol ensures transparency in the methods used during the process, which makes it easier for researchers to use your study and reproduce knowledge from it.
- A protocol can help save time by describing the research process before it is implemented. This streamlines the review and is less time-consuming.
- Many journals require standard protocols for systematic reviews so that it can be determined whether your review meets the eligibility criteria.
- A registered protocol reduces the chances of multiple reviews being replicated on the same research question.
- Since a systematic review protocol mentions the inclusion and exclusion of studies beforehand, it minimises the risk of research bias being incorporated into the review process. This is why a systematic review is termed objective in terms of its findings and conclusions.
How To Write A Protocol For A Systematic Review
Here is a step-by-step guide to writing a protocol for a systematic review:
- Define a Research Question
The first step in writing a protocol for a systematic review is to define the research question for the review process. It should be clear, concise and relevant.
- Define The Criteria
Defining the eligibility criteria for the systematic review is the most crucial part of the protocol. This means discussing the inclusion and exclusion of different studies and research papers for the review. By doing this, a clear roadmap is set for the researchers. For instance you may choose to include studies that were published in the last 15 years and choose to exclude studies that are not published in languages other than English.
- Conduct Literature Search
Conduct a comprehensive literature search by utilising online and electronic databases such as Google Scholar, PubMed and other sources that are credible and reliable for systematic review protocols. Moreover, the focus must not only be on published literature but also on unpublished literature, known as grey literature. For effective search strategies, combine keywords using Boolean operators.
- Choosing Quality Assessment Tools
Develop a plan for assessing the quality of the evidence by defining criteria that are relevant to your research question. Use tools for quality assessment such as the Cochrane Collaboration Risk of Bias tool that is used for randomised-controlled tests that cover areas such as binding, randomisation, selective reporting and other types of biases. The Newcastle Ottawa scale and STROBE checklist are widely used Q/A tools for observational studies.
- Data Extraction & Management
Data extraction is the process of extracting relevant pieces of information from different sources to synthesise the studies and draw conclusions from them. It is recommended that more than one person extract data from every included report in order to minimise errors and reduce bias. Additionally, the process of data extraction should be tracked using a standardised data extraction form and while it is under process, it is important to use data management tools to avoid discrepancies. Some well-known data management tools and software for systematic reviews are:
- Covidence
- Cochrane Data Management Tools
- Rayyan
- RefWorks
- Endnote
- Data Synthesis
It is important to discuss the variability of the studies and how you will manage them. Moreover, decide how you will combine and synthesise the data and what methods you will use, such as meta-analysis or narrative synthesis.
- Timeline & Resources
Allocating the timeline of the review is a crucial part of the protocol. It is imperative to mention the key milestones that will be reached and the different phases of the process of conducting a systematic review. Moreover, it is essential to mention the allocation of resources such as personnel, software, tools and databases.
- PRISMA
While writing and designing your protocol, remember to refer to the guiding framework and reporting tool, known as preferred reporting items for systematic reviews and meta-analysis protocol, which is a 27-item checklist that mentions the items that need to be reported along with the methods and results. This helps you remember all the essential elements needed to ensure clarity and completeness.
- Approval And Dissemination
The last step is to review your protocol and make changes needed according to the objectives and aims of the systematic review. You can also seek feedback from your peers and other researchers. Last, you should register your protocol in various journals to create awareness among other reviewers and avoid replication of your work.
Example Of Protocol For Systematic Review
To best understand how to write protocols for systematic review, let’s explore an example:
Example 1: Systematic Review Protocol On Smoking Cessation Interventions
Research Question:
What are the current best practices regarding smoking cessation interventions for hospitalised patients?
Eligibility Criteria
- Studies that include hospitalised patients who smoke
- Studies that include non-hospitalised patients where interventions can be applied in a hospital setting.
- All studies evaluating the effectiveness or efficacy of interventions and strategies related to smoking cessation for hospitalised patients.
Data Extraction & Management
Data will be managed using a data management tool i.e. RefWorks, and extracted using a standardised data extraction form. Moreover, two reviews will independently perform the data extraction.
Assessment of Risk Bias:
The Cochrane Risk Of Bias assessment tool will be used to determine the quality of the data collection.
Data Synthesis
Results from comparable studies will be pooled for statistical meta-analysis using Reviewer Manager software from Cochrane Collaboration. Where statistical pooling is not possible, the results will be presented in textual form. For qualitative data, where meta-synthesis is possible, textual data will be pooled using the Qualitative Assessment and Review Instrument (JBI-QARI).
Publication Bias
To assess publication bias, comprehensive search strategies will be employed to identify both published and unpublished studies. Moreover, by using trim and fill analysis, the number of missing studies can be determined.
Good Journals For Systematic Review Protocols
It is an essential part of a systematic review to publish its protocols in a reputed and well-known journal. Let’s explore some suitable journals for publishing systematic review protocols.
- Systematic Reviews
- Joanna Briggs Institute
- BMJ Open Science
- Cochrane database of systematic reviews
- BMC Systematic Reviews
- JAMA
- PLOS ONE
- PROSPERO
- Campbell Systematic Reviews
Ethical Considerations For Systematic Review Protocols
Ethical considerations are a critical aspect of any academic research. Similarly, these must be taken into view so that the integrity and credibility of your systematic review are never brought into question. Here are some important ethical considerations to keep in mind:
- Ensure transparent reporting
- Avoid research misconduct and collect data by ethical means.
- Maintain confidentiality of participants.
- Be aware of the cultural sensitivities during the review process.
- Proper citations to avoid plagiarism.
- Practice informed consent.
Frequently Asked Questions
The essential elements of a research protocol are the objectives, research question, methodology approaches, search terms & strategies, inclusion and exclusion of studies, data extraction and analysis plans.
It is essential to register your systematic review protocol to ensure transparency, and avoid duplication or multiple reviews answering the same research question. Moreover, registering it increases the cache of potential communication with other researchers.
The Cochrane protocol was introduced by the Cochrane Collaboration and is a structured guideline and framework for conducting systematic reviews. It specifies the methods to be used, the data extraction strategies, and inclusion and exclusion criteria for analysing results. By following this framework, researchers reduce bias, improve the reliability of their findings, and structure the protocol well.
The PRISMA, also known as preferred reporting items for systematic reviews and meta-analysis protocol, is a 27-item checklist that ensures that the systematic reviews are reported accurately and transparently. It does not check for eligibility of the review to be published for any journal but ensures that the review process is complete and has the ability to be reproduced again depending on the methods used.
