In principle, participant contact information and consent forms should be deleted once the data collection of a research project is completed. The exception is when consent is the legal basis for the processing of personal data. Consent forms should then be retained as long as the data remains identifiable. For other exceptions, see the section below.

Contact details or consent forms may not be stored with the purpose to verify at a later stage whether a person actually participated in the study. In addition, they may not be stored for the sole purpose of allowing participants the option to withdraw their data from the study.

For research conducted anonymously or where the legal basis for processing personal data is ‘public interest,’ consent forms may be used without including the participant’s name and signature. We have templates available that use a checkbox instead of a signature. This reduces the amount of personal data collected in these instances.

Exceptions:

• Longitudinal Research
  Contact information and consent forms may be retained if the research is longitudinal in nature and participants may be re-contacted in the future. Finalized funding is not necessary for this. In this case, contact information must be stored separately and securely from other data (i.e. pseudonymized, allowing for the combining of newly collected to existing data).
  Participants must give explicit consent to be re-contacted for future research (via a separate option). If this consent is not given, both the consent forms and the contact information must be deleted.
  When consent is obtained separately for different aspects of data collection or processing (for instance, consent for a questionnaire but not for a follow-up interview), the consent forms must be kept to verify which permissions were granted.
• Legal basis for the processing of personal data
  Consent forms must be retained for identifiable personal data where consent is the basis for processing.
• Medical scientific research (Dutch: WMO-plichtig)
  Consent forms must be retained in their original state. The ICH-GCP guideline allows original paper documents to be replaced by certified digital copies. These copies must undergo a validation and authorization process to be recognized by supervisory authorities. Since there is no uniform guideline for validating these copies, the NFU advises retaining paper documents with original signatures and not destroying them.