Jessica and Heidi– you have highlighted some of the complexity related to decision-making on this issue. When new tools are added to the standard of prevention, HIV incidence is likely to decrease and then the statistical power of the trial to detect significant differences decreases–so demonstrating efficacy becomes more challenging…in the long-term, trials will have to enroll many more participants, resulting in much more time and cost! And –ultimately–invalid trial results is an ethical issue, because it means that participants will have been exposed to risks for no real purpose…
So perhaps things like standards of evidence, the threshold (at which adding new tools will invalidate trial results), and processes for decision making should be explored– as part of early stakeholder consultation and negotiation?
