A systematic review of literature is a rigorous and comprehensive approach to identifying, evaluating, and synthesising all available evidence on a specific research question. It involves a structured and transparent process that follows a predefined protocol to minimise bias and provide an objective summary of the existing evidence. This blog will provide a step-by-step guide on how to conduct a comprehensive systematic review of the literature.
Understanding Systematic Reviews: Purpose in Research
An extensive analysis of the body of literature that provides answers to specifically formulated questions is known as a systematic review. The review methodically finds, identifies, assesses, and synthesises research findings relevant to the topic at hand using a research approach that is explicit, reproducible, and reduces bias. The best source of scientific evidence is thought to be systematic reviews. In the field of evidence-based medicine, systematic reviews are essential, but they are also highly regarded in other disciplines.
A systematic review is more thorough than a literature review because it contains both published and unpublished literature often known as grey literature.
Process of Conducting a Systematic Review
Defining the Research Question and Objectives
Developing a research question is the first stage in performing a systematic review. From this point forward, every decision will be based on the research question, thus it is critical to consider all options, consult widely, and define clearly.
A knowledge gap should be filled by the review. Checking Prospero databases will give you an idea of what systematic reviews are already out there. Consider the audience for the review, this will ensure that the review is relevant.
Think about scope. Numerous elements will determine whether to have a broad or narrow emphasis. A broad scope can help you do comprehensive research but demand significant resources. A focused area of study may be easier to manage, but there won’t be enough data to create a useful synthesis. Consider adopting a platform like Covidence to organise the study data, document the decision-making process, and monitor progress if the review is going to produce a significant amount of evidence.
Applying Inclusion and Exclusion Criteria
As we said before, from the point you choose your research question, everything will depend on it. The same is the case with the inclusion and exclusion criteria. This is part of the process you need to identify the criteria that you will use to determine which research studies will be included and which studies will be excluded.
Exclusion criteria are the features that would exclude a study from inclusion, whereas inclusion criteria refer to all the studies and sources you will include in your evaluation. You must specify your inclusion requirements. For instance, you can limit the review to works produced by authors with specified qualifications or from a specific country or region or works published during the last five years. When deciding on inclusion criteria, you should also take your target audience and the objective of the review into account. It will be simpler for you to locate relevant literature for your systematic review if your inclusion criteria are more precise and specific.
Conducting the Initial Literature Screening
Once the research question and inclusion and exclusion criteria have been established, a comprehensive search for relevant studies should be conducted. This can involve searching electronic databases, reference lists, and grey literature. The literature search strategy should be transparent, reproducible, and comprehensive to ensure that all relevant studies are captured.
Literature Screening and Selection of Studies
After the initial search has been conducted, the next step is to screen and select studies based on the inclusion and exclusion criteria. This can involve screening titles and abstracts, followed by a full-text screening of potentially relevant studies. Screening should be conducted by at least two independent reviewers to minimise bias, and any discrepancies should be resolved through discussion or consultation with a third reviewer.
Data Extraction and Quality Assessment
Once the studies have been selected, data should be extracted and a quality assessment should be conducted. Data extraction should involve the systematic and transparent extraction of relevant data from each study, while quality assessment refers to quality appraisal, critical appraisal and risk of bias assessment should involve the critical appraisal of the methodological quality of each study.
Synthesising the Findings
The next step is to synthesise the findings of the included studies. This can involve a quantitative meta-analysis or a qualitative synthesis, depending on the nature of the research question and the available evidence. The aim of data synthesis is to provide a summary of the evidence, which can be used to answer the research question of the review. The synthesis should be structured, transparent, and reproducible, and any inconsistency in the findings should be explored and explained.
Structuring Your Literature Review
The final step is to write your systematic review. Structuring your systematic review is the most important part of writing it, so make sure that you follow the structure perfectly. The review should include the following sections:
To ensure that your review includes everything, you can use the PRISMA checklist.
Conducting a systematic review takes a considerable amount of time and effort but by following the steps outlined in this blog you help you produce a robust and reliable review.