Publishing human studies requires more than just scientific integrity and solid data. Above all, it requires the protection of the dignity, privacy and health of the human beings involved. Understanding the requirements for publishing studies involving humans will help authors protect patients both during and after publishing the study.

Here, we will cover key international ethics standards authors should adhere to and specific documentation that may be requested by journals during submission.

The Declaration of Helsinki: a global standard

Since ancient times, ethical codes of conduct such as the Hippocratic Oath have been created to emphasize the physician’s duty to do no harm, respect the patient and uphold professional integrity. But medical research is no longer limited to just physicians.

To address modern ethical concerns and include all those performing research involving human participants, the World Medical Association developed a set of ethical principles known as The Declaration of Helsinki of 1964.

The Declaration of Helsinki is now considered one of the most important documents in research ethics and has been adopted as a global standard. The basic principles mandate that the health, rights and well-being of individuals must be prioritized above all else. Risks, burdens and benefits must be carefully considered and monitored throughout the research process to assess if the research should be stopped, modified or can continue as planned.

In October 2024, the declaration was updated to stress the importance of the individuals volunteering to be a part of the research. Terminology was changed to refer to these individuals as “participants” and not “subjects”, highlighting the importance of community engagement and participant-centered inclusion.

Other important updates highlight the need for improved transparency, stricter rules on data sharing, increased protection for vulnerable populations and, overall, a stronger commitment to fairness and equity in research.

The Declaration of Helsinki also provides guidance on required approvals before research on human participants can be undertaken. This includes approvals from:

• The Research Ethics Committee that will evaluate, approve and monitor the study.
• The participant or legal representative that freely provides consent after receiving all necessary information regarding the study.

Publishers will usually ask for detailed statements regarding these approvals, so knowing exactly what to include can avoid delays or desk rejection.

What to include in the Institutional Review Board statement

Point 23 of the Declaration of Helsinki requires researchers to submit their full research plan to an ethics committee for evaluation prior to beginning their actual research. This committee is commonly referred to as an Institutional Review Board (IRB).

The IRB independently evaluates the research plan, considering ethical, legal, and regulatory norms and standards of the country where the research will be conducted. This committee will also be responsible for monitoring compliance throughout the whole duration of the research.

Upon approval, the committee will provide authors with an official approval letter together with an identification code that is unique for the specific project.

When submitting an article, authors will need to include the official name of the IRB, the project identification code and date of approval within the “Institutional Review Board Statement” section. An example of a complete IRB statement could be:

“The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of XXX (Project identification code) on [date of approval].”

Do all studies involving humans require ethical approval?

Not all human studies require ethical approval. In some cases of non-interventional studies with low risk and ensured anonymity, IRB approval may be waived. However, even in these cases, if the participants are from a vulnerable group, for example children, approval may be required.

The US Department of Health and Human Services provides researchers with a series of decision charts to determine if their research requires approval or not.

Determining if your research is exempt from ethical approvals can be complicated, so the best course of action is to ask the local ethics committee to evaluate and provide an exemption, if deemed appropriate.

If an ethics committee was not consulted to provide an exemption, authors are required to cite the local or national legislation that indicates ethics approval is not required for their type of study. The journal will review the case in detail and determine if it is a low-risk study and can be exempted according to local legislation.

The Committee on Publication Ethics provides guidance for editors regarding factors they should consider during this evaluation.

How to report research involving organ transplants

In addition to adhering to all policies and guidelines involving human participants, articles reporting research involving organ transplants need to include further specific information.

Within the IRB statement, authors must specify the institution(s), clinic(s), or department(s) from which the organs or tissues were sourced.

MDPI does not accept manuscripts that report data on organs and/or other materials obtained from illegal commercial activity, executed prisoners, or other unethical practices relating to organ donations.

For further resources on organ transplantation, MDPI follows the glossary maintained by the Organ Procurement and Transplantation Network.

Obtaining consent for human studies

The Declaration of Helsinki states that “free and informed consent is an essential component of respect for individual autonomy”.

Manuscripts reporting studies involving human participants, data, or biological material must include a statement of informed consent for participation in the research.

Consent must be given freely and voluntarily by the participant or legal representative. The participant should always be free to decline or withdraw consent without any adverse effects on the standard of care.

Participants are usually provided with a consent form detailing the aims, methods, benefits and risks of the study as well as information regarding privacy, confidentiality and any other aspects of the research.

Publishers may request a non-signed informed consent form to be uploaded upon submission. In some rare cases, verbal informed consent may be acceptable. However, a copy of the script used to obtain consent should be provided during submission.

Participant privacy

Researchers must take precautions to protect the privacy of all participants. Any information that may be used to identify the participants should be carefully removed from the manuscript.

There are two types of identifiers:

• Direct Identifiers: details that can be used to identify a person without the need of any additional information. Examples include patient name, identity numbers, biometric data, or images that include facial features.
• Indirect Identifiers: details that cannot be used to identify a person when given alone; however, when connected with other direct or indirect identifiers, they may be used to identify the person. Examples include occupation, race, religion, geographical locations, medical condition.

Indirect identifiers should be limited, as including 3 or more may lead to participant identification. Direct identifiers should be completely removed to retain anonymization.

In some cases, the identity of the participant cannot be fully anonymized, and identifiable information must be included as it is of relevance to the research. For example, photographs depicting a participant’s face to show a particular symptom may be needed.

When authors cannot avoid the inclusion of identifying participant information, written informed consent for the publication of these details must be obtained.

Participants should be provided with the submission version of the article, including all text, figures and supplementary materials. The participant must also be informed where the article will be submitted and especially if the article will be published online in an Open Access format.

Publishing an article in an Open Access journal means that the participant’s private information can be freely accessed, downloaded, copied and reused by anyone across the globe. Participants should be aware of this and allowed to withdraw their consent at any time prior to publication.

To assist authors with correctly obtaining permission, MDPI provides authors with a template permission form and encourages authors to also consult with their affiliated institutions.

Special considerations of vulnerable groups

Vulnerable individuals, groups or even communities require special consideration and protection. Inclusion of vulnerable individuals, groups or communities in medical research is warranted only if there is a clear health need and benefit. But at the same time, researchers should evaluate if exclusion can lead to increased disparities.

To ensure research integrity and the highest standards of publication ethics are met, manuscripts involving vulnerable groups will undergo additional review prior to peer-review.

Authors should be prepared to provide any additional documentary evidence upon request, including blank consent forms and any related discussion documents from the IRB or other relevant bodies.

Open Access and ethical practices

Within point 36 of the Declaration of Helsinki, the ethical responsibilities of researchers to ensure the dissemination of medical research results are highlighted:

“Researchers have a duty to make publicly available the results of their research on human participants and are accountable for the timeliness, completeness, and accuracy of their reports”.

This includes publishing negative or inconclusive results and not only positive results. Therefore, it is also the responsibility of publishers to offer authors the opportunity to publish and disseminate these results.

Publishing negative results still contributes to the overall understanding and prioritizes transparency and patient safety. If, during a study, it is determined that a treatment has no benefit, or could potentially harm a patient, this information must be shared without restrictions and openly with the entire research community.

MDPI’s philosophy and mission are closely aligned with this principle, and we will continue to encourage authors to publish all their findings, including negative results openly.

Ethical and responsible Open Access publishing

Human studies are essential to further our understanding of diseases and how to treat them. However, protecting the privacy and health of the human participants should always be prioritized.

MDPI is committed to ensuring that all research adheres to the principles and standards outlined in the Declaration of Helsinki. Authors are required to provide a complete IRB statement that contains the IRB name, project code and date of approval. Where informed consent is required, authors must confirm that it was obtained and provide the blank informed consent form during submission.

The statements provided and documentation will be carefully reviewed to ensure the highest ethical standards are met.

Learn more about how Open Access strengthens research integrity or visit our Research and Publication Ethics page for more guidance on publishing research involving human studies.