A strategy for measuring patient preferences to incorporate in benefit-risk assessment of new ophthalmic devices and procedures

The U.S. Food and Drug Administration recently released guidance documents explaining that measurement of patient preferences should be considered during the pre-market approval process to specify patients' tolerances for risk and perspectives on benefit when assessing the benefit-risk profile of new medical devices. For ophthalmological patients, the typical primary clinical outcome is a visual impairment measure. Especially for surgically- implanted devices, the benefit a specified improvement in vision measures must be translated to a patient-specific benefit of the improvement in ability to function in everyday life. We developed, and validated with simulations, a strategy for measuring an individual patient's ability to function and the overall benefit to that patient of specified improvements in functional ability. Our strategy employs Rasch analysis to measure changes in functional ability; multidimensional scaling to measure patient-specific benefits of changes in functional ability; and structural equation modeling to cross-walk patient preferences for functional ability changes to changes in visual impairment measures.