What must be included in consent documents to allow for re-contacting subjects?

Including a clause that specifies the conditions under which subjects can be re-contacted is essential in consent documents because it provides clarity and transparency to the participants about how their information will be used in the future. This clause informs participants of the specific circumstances that would warrant re-contacting them, which helps establish trust and ensures they are fully aware of their rights regarding their data.

When subjects understand when and why they might be contacted again, it promotes ethical research practices by allowing participants to make informed decisions about their involvement. Consequently, this is crucial for maintaining ethical standards in research, ensuring that consent is truly informed and that participants feel respected and secure in their participation.

Overall, the correct choice acknowledges the importance of detailed informed consent, particularly regarding communication and participant autonomy about future contact.