Patient perspectives on medical device development are becoming much more central to the U.S. FDA’s regulation of devices, thus the August 2020 draft guidance for selection of patient-reported outcome (PRO) instruments for device evaluation. However, the draft is sufficiently vague on the question of when an existing PRO can be tweaked without an entirely new validation study to prompt the Advanced Medical Technology Association (Advamed) to press the agency for more clarity on that point.