When must informed consent be obtained?

• A. Before any study-specific procedures
• B. During screening visits
• C. After enrollment
• D. At the end of the study

Answer: (A)

Informed consent must be obtained before any study-specific procedures begin. This means when a participant is about to undergo any activity that is part of the research protocol—such as screening tests, interventions, or data collection—the participant must have given voluntary, informed permission beforehand. Obtaining consent at this point ensures the person understands the purpose, risks, benefits, and rights, and that participation is voluntary.

If you wait until screening to obtain consent, or delay until after enrollment or to the end of the study, that would allow procedures to occur without proper permission, which is unethical and violates regulatory standards. In practice, if screening involves any study-related procedures, consent should be obtained before those procedures are performed.