Human subjects and their consent
Research often involves working with human participants and in particular methodological tools, e.g., surveys, questionnaires, interviews, standardised tests, direct observations, ethnography, recording experiments with volunteers, physical interventions of all sorts. Because of the possible impact of research practices, researchers must carefully reflect the ethical implications of the chosen subjects, methodologies and consider ways to mitigate the harm (psychological, social, legal, economic, environmental, etc.) that might occur. Research entailing more than minimal risk typically involves:
- potentially vulnerable categories of individuals such as children/minors, patients, people subject to discrimination, people/groups unable to give consent, people of dissenting opinion, immigrant, minority communities, sex workers, etc.
- personal or sensitive topics which might induce psychological stress, anxiety or humiliation, dissenting voices, critique towards others, etc.
- deception
- seeking respondents through the internet/social media (e.g., using identifiable visual images or discussing sensitive issues)
- …
Prior risk-benefit assessment is always crucial in the research design.
When performing studies with human participants, there are a number of biases you should take into account when setting up your study. The list below is not exhaustive but gives you an idea of potential pitfalls.
Non-response bias
“A bias that occurs due to the systematic differences between responders and non-responders.”
It might be that participants who do not respond to your invitation to participate in the study may differ substantially, e.g., outlook, constitution, etc. from those who do. If you are not aware of this bias when setting up your research, this might result in formulating faulty population characteristics.
Observer bias
“The process of observing and recording information which includes systematic discrepancies from the truth.”
This type of bias might occur in observational and interventional studies, given that the observer involved is a human being prone to subjectivity and that empirical perceptions can differ from one person to the next. An observed value is hence not always a true value. “Where subjective judgement is part of the observation, there is great potential for variability between observers, and some of these differences might be systematic and lead to bias”.
Volunteer bias
“Participants volunteering to take part in a study intrinsically have different characteristics from the general population of interest”.
If you perform a study with human test subjects, you would like your set of participants to be as representative for the whole population as possible. If you are working with volunteers, prior studies have shown that this is not always the case. This might have to do with socio-demographic factors, attitudes towards the trials or the institutions involved, but also with the topic of the study (e.g studies on drug use).
All definitions and clarifications are either direct citations or paraphrases from the definitions given in the Catalogue of Bias.
Informed consent
Research participation must at all times be entirely voluntary. To be able to make this decision as a participant, researchers must inform them as consciously and deliberately as possible. Researchers must obtain and clearly document participant’s informed consent prior to their participation in the research.
Important to note is the distinction between providing consent to participate in a research study (‘ethical consent’) and consent as a legal basis for processing personal data. For ethical reasons, you may need participants’ consent to participate in a specific study (this may be legally required or ethically recommended). Such ethical consent for the participation in a research study does not necessarily equal consent as the legal basis for processing personal data.
Cartoon by Patrick Hochstenbach under a Creative Commons CC BY-SA 4.0 license
Key principles of informed consent
Participants must be given an informed consent form and a detailed information sheet that:
- is written in a language and in terms they can understand (the language used must be understandable for a 14-year-old)
- describes the aims, methods and implications of the research, the nature of the participation and any benefits, risks or discomfort that might ensue.
- clearly communicates the burden of the research participant and ensures it’s reasonable and proportional.
- explicitly states that participation is voluntary, and the participants have the right to refuse participation and to withdraw their participation, at any time and for no reason.
- states how biological samples and data will be collected and protected during the project, and, either destroyed or reused subsequently.
- states what procedures will be implemented in the event of unexpected or incidental findings (in particular, whether the participants have the right to know, or not to know, about any such findings).
- states the procedures for sound research data management that will be put into place (see below).
It must be ensured that potential participants have fully understood the information and do not feel pressured or coerced into giving consent. Participants must normally give their consent in writing (e.g., by signing the informed consent and information sheets).
‘I offer my students (extra) course credits when they participate in my research project as a research participant.’
When conducting research with participants who are in some way in a relationship of dependence with them (students/clients/staff), the researchers will take the necessary measures to protect the latter from any adverse consequences of termination or refusal of participation. In cases where (extra) course credit is offered, students should be notified of alternative means of obtaining the same amount of credit. Such alternatives must be comparable in terms of time and effort.
When getting consent requires extra attention
In some cases, participants are unable to give consent even though the research has a significant value.
These projects may only be carried out if:
- studies with consenting adults would not be effective
- participants are subject to only a minimal risk and burden
- the results of the research will benefit the individual or the group they represent.
Research involving persons who are physically or mentally incapable of giving their consent (for example unconscious patients, elderly suffering from severe cognitive impairment, persons judged as lacking mental capacity), may only be conducted if the physical or mental state that prevents them from giving consent is a necessary characteristic of the group covered by the investigation. In such circumstances, the researcher should request the informed consent of the legal representative and maintain an active relationship with them throughout the research period. Whenever possible the assent, being the affirmative agreement, of the actual participant should be obtained in addition to the consent of the legal representative. In the absence of a legal representative and if the investigation cannot be postponed, the intervention may be started without the informed consent, following conditions and procedures approved by the relevant ethics committee and if it meets the conditions described in the relevant law. Permission to keep the person involved within the investigation must be obtained as quickly as possible from the person himself or from his legal representative.
Minor participants are a special category in this group. When collecting data from minors, and you obtain parental consent, don’t forget to obtain assent of the child, so that they also have the opportunity to clarify their wishes, irrespective of their age. There can also be cases where the consent by the minor is sufficient.
In case of a dissent by the child (in contradiction with the consent of the parent), researchers should respect the wishes of the child. Researchers should maintain an active relationship with the parents/legal guardians/caretakers throughout the research period.
If consent cannot be given in writing, for example because of illiteracy, non-written consent must be formally documented and independently witnessed, i.e., by a person who isn’t involved in the study or associated with the research actors nor does have personal interest/benefit in the outcome of the study. There will be situations where standard procedures for obtaining written informed consent could be harmful or offensive to the participants, e.g., minority groups, with particular distrust towards official authorities or possible critical or personal (e.g., on sexual orientation) statements could be dangerous, etc. In such cases, alternative consent needs to be gained (e.g., orally).
Deception
Some research activities or experiments make use of deception. Deception requires strong justification and appropriate assessment of the impact and the risk incurred by both researchers and participants. Retrospective informed consent should be obtained as soon as possible, and participants must also be debriefed.
Data management in informed consent
Besides the ethical aspects dealing with participants itself, there can also be ethical requirements related to the data that need additional clarification and approval of the participant via the informed consent.
- Communication on the data should avoid professional jargon and focus on the added value for participants e.g., the security of data storage, policy on sharing and reuse of the data, anonymization, etc.
- To ensure that data are kept securely, and that publication of any kind does not lead (either directly or indirectly) to a breach of agreed confidentiality and anonymity, extra care and special attention needs to be given to the (technical) aspects of collecting and storing your research data. Even so when electronic encoding tools are used.
- In relation to working with human participants and personal data, extra measures need to be taken.
Because research is a dynamic process and can contain different legal and ethical issues in the same project, it is advised to contact your local ethics committee to align all requirements especially in complex and sensitive topics. Due to the dynamic nature of research, it is important to recognise that ethics is not a mere checkbox exercise and that after obtaining ethics approval, new ethics issues may arise that require a new check by the ethics committee.