Preparation and Rationale for a Patient-Reported Clinical Outcome Assessment Set of Fluid Overload for Drug Development in Nephrotic Syndrome

Introduction: Fluid overload is a source of substantial morbidity for adults and children with nephrotic syndrome (NS). Preparation and Rationale for a Fluid Overload in Nephrotic Syndrome Clinical Outcomes Assessment Set for Drug Development (Prepare-NS, 5UG3FD007308) was funded by the US Food and Drug Administration to develop a core set of patient-reported and observer-reported (for young children) outcome measures of fluid overload for use in pharmaceutical trials across the lifespan. Methods: The Prepare-NS study team developed the proposed context of use with input from stakeholders. We conducted a scoping review to assess the available literature on relevant patient- and observer-reported measures and performed secondary analyses of existing qualitative and quantitative data. Results: The outcome set will aim to serve individuals 2 years of age and older with primary NS conditions (specifically focal segmental glomerulosclerosis, minimal change disease, IgM nephropathy, membranous nephropathy, and childhood-onset NS not biopsied). The existing literature describing patient-reported outcomes in NS largely relies on nonspecific measures of health-related quality of life; fluid overload has been associated with lower scores on these measures. Conclusion: To address the gap in measure availability and fluid overload content, the Prepare-NS team has launched a set of qualitative studies for concept elicitation from the population of interest to inform development of new measures. The resulting measures subsequently will undergo psychometric evaluation and validation in a survey study.