How should payments to trial participants be structured?

• A. Payments to participants should be made only at trial completion.
• B. Payments should be timely, prorated, and not wholly contingent on completion of the trial.
• C. Payments should be provided only if the participant adheres to the protocol.
• D. Payments should be awarded randomly.

Answer: (B)

Fair, non-coercive participant compensation should reflect the time, burden, and any expenses of taking part in the study. It should be provided promptly and in a prorated way, so someone who contributes part of the way through the trial is paid for that portion, not penalized for leaving early. Crucially, payments should not be contingent on completing the trial; tying compensation to completion can create undue influence or bias, pressuring participants to stay or continue reporting in ways that compromise study integrity. In practice, this means reimbursing reasonable expenses (like travel) and compensating for time and inconvenience in a timely, proportional manner.