Many researchers—especially those new to evidence synthesis—often wonder whether ethical approval is required when conducting a systematic review. This is a valid concern, given the centrality of ethics in all scientific research. However, the answer is generally straightforward: systematic reviews do not require ethical approval, as they are based exclusively on publicly available data rather than new data collection involving human subjects or animals.
Systematic reviews typically synthesize findings from previously published studies that have already undergone ethical scrutiny during their original investigations. Because these reviews do not involve interaction with participants, collection of sensitive personal information, or any form of intervention, they are exempt from institutional review board (IRB) or ethics committee approval in most cases.
In line with this, the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)—which serve as the gold standard for reporting systematic reviews—do not mandate the inclusion of an ethics statement in the methods section. This is consistent with other widely accepted guidelines, such as those from Cochrane and the Joanna Briggs Institute (JBI), which also do not require ethical approval for reviews of published data.
Scientific Integrity and Ethical Responsibilities
That said, the absence of a requirement for formal ethical approval does not mean that ethical considerations are irrelevant in systematic reviews. Researchers must still adhere to the highest standards of scientific rigor and ethical conduct throughout the review process. Key ethical principles include:
Transparency: Researchers should clearly document the review protocol, search strategy, inclusion and exclusion criteria, data extraction methods, and any deviations from the original plan. Registering the review protocol (e.g., in PROSPERO) enhances transparency.
Honesty: All findings should be reported accurately and without manipulation. Selective reporting, data misrepresentation, or suppression of unfavorable results compromises the integrity of the review.
Accountability: Authors are responsible for the accuracy and reliability of their findings and should be prepared to explain and defend their methods and conclusions.
Reproducibility: Others should be able to reproduce the review process by following the described methods. This strengthens the credibility of the review and supports evidence-based decision-making.
Respect for Intellectual Property: Proper attribution and citation of original studies and ideas are essential. Plagiarism in any form, including the inappropriate use of others’ work or ideas, must be strictly avoided.
Avoidance of Bias: Reviewers must strive to minimize biases in study selection, data interpretation, and reporting. Declaring conflicts of interest and funding sources is critical to maintaining trustworthiness.
Conclusion
While systematic reviews are exempt from formal ethical approval due to their use of already published data, they are not exempt from ethical responsibility. Researchers must uphold core values such as transparency, honesty, accountability, and respect for others' work. In doing so, they contribute to the reliability, credibility, and value of scientific knowledge synthesis.
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