How to write an informed consent form 

Participants must have a real choice whether to participate or not. Although coercion and intimidation are obvious violations, be aware that disproportionate compensation and power imbalances should also be avoided. For example, students must not feel compelled to consent to a research study for the sake of their studies, nor should any participant consent because the compensation is vital to their survival or quality of life.
 

Research projects can often involve multiple types of processing. In such cases, the participants should be free to choose which purpose they accept, rather than having to consent to a bundle. For example, if a research project involves behavioral tests, interviews and surveys; the participant should be able to consent to each process separately if they are not all necessary for participation in your project.

The concept of specificity also extends to the way in which the collected data is going to be used. Thus, the data should only be used for the purpose for which it was specified in the information sheet. Since this would compromise your ability to share data, the re-use of data for research purposes is allowed under the GDPR. To be able to share your data for reuse purposes for research, you must ensure that participants have been informed about the intent to share and the data should be adequately safeguarded with clear security and privacy measures (i.e., secure storage, access restriction, pseudonymization, aggregation and minimization). 

Providing information is essential to a valid consent. How the information is provided however need not always be through a written information sheet. This means valid information may be presented in other ways, such as oral statements, or audio/video messages. 

The information provided must be clear and understandable and “the action of giving consent” has to be unquestionable and explicit. To demonstrate a clear affirmative action, the participant must take a deliberate action. For this reason, pre-ticked opt-out boxes are invalid, since they require no action from the participant. Ambiguity can also be avoided by providing participants with the option to tick a “NO” or a “YES” box, instead of only a “YES” box. The deliberate action of consent can be both a written (e.g., ticking a box, writing an email) or a recorded oral statement.  

In research, signing a consent form is rarely needed, as it often leads to the collection of unnecessary personal data, and a consent form is not a binding document anyways (it can be withdrawn at any point). Therefore, a signature only makes sense if the identity of the individuals is meant to be used in the process (e.g., in clinical trials), since that does not lead to additional data collection. If your research does not require the collection of names, or is using pseudonyms, using a signature leads to the collection of unnecessary personal data and is therefore not necessary. A check box (and possibly a statement/signature of the person/researcher who collected the consent) is often sufficient. 

Information sheets and consent forms should address the possibility of sharing data, future data publication (including storage in a repository) or long-term retention of data for verification. In this way informed consent from research participants can be obtained.

• State the conditions under which access to the data may be granted to others. E.g., sensitive data can be safely shared through mediated/controlled access, specific user agreements, de-identification and custom approval by the original research team. In some cases, it may also be appropriate to provide an opportunity for participants to select whom they agree to share their data with (and with whom they don't). 
• Statements about data publication and sharing in participant consent forms should: 
  • Explain that you as a researcher have an obligation to protect your subject's confidentiality and that you will only share the study data with the broad scientific community by retaining this confidentiality. 
  • Indicate how data will be de-identified in practice (e.g., by removing all personal information that could directly identify an individual). 
  • State when the retention of personally identifiable information expires. 
  • Consent should be documented with the collected data so subsequent users of the data are aware of the conditions agreed upon with participants. 

If statements only mention the current study, sharing is not explicitly possible. You should add a sentence to make it clear to participants that the data could be used for further research, de-identified where possible, or identifiable with enough safeguards and security measures. 

Try to avoid putting this in your consent form: 

• Terms such as 'fully anonymous' or 'strictly confidential' as they are often impossible to achieve. 
• Promises to destroy data. 
• The mention of an expiration time period for the consent. 
• Promises that the data will only be seen or accessed by the research team.

Sensitive data can legally be shared without explicit consent if the information given to participants prior to their consent for data collection indicated future use of the data, or if ALL of the following are applicable:

• The opportunity to gain consent no longer exists or is not practical.
• The data have been de-identified. 
• There is no risk that publishing or sharing the data will cause harm or contribute to discrimination towards the research participants or subjects. 
• Information sheets and consent forms from the original data collection did not preclude sharing. 
• “Any personal information that could reasonably identify you will be removed or changed before files are shared with other researchers or results are made public." 
• "If you decide to be in this study, the study researchers will get information that identifies you and your personal health information. This may include information that might directly identify you, such as your name and address. This information will be kept for the length of the study and a fixed period afterwards (x-years). After that time, it will be destroyed or de-identified, meaning we will replace your identifying information with a code that does not directly identify you.” 
• “The principal investigator will keep a link that identifies you to your coded information, but this link will be kept secure and available only to the principal investigator or selected members of the research team. Any information that can identify you will remain confidential.” 
• “The information in this study will only be used in ways that will not reveal who you are. You will not be identified in any publication from this study or in any data files shared with other researchers. Your participation in this study is confidential.” 
• “Other genuine researchers [may] have access to this data only if they agree to preserve the confidentiality of the information as requested in this form.” 
• “Other genuine researchers may request access to de-identified data in the future. Access will only be granted if they agree to preserve the confidentiality of the information as requested in this form. Their access will also require approval from the original research team." 
• “If you withdraw from the study, you do not have to state why. Please do inform the researcher about your decision. All data already collected up until that moment will be used for the current and future research.”