Core Outcome Domains for Trials in Autosomal Dominant Polycystic Kidney Disease: An International Delphi Survey

Abstract

Outcomes reported in trials involving patients with autosomal dominant polycystic kidney disease (ADPKD) are heterogeneous and rarely include patient-reported outcomes. We aimed to identify critically important consensus-based core outcome domains to be reported in trials in ADPKD. An international 2-round online Delphi survey was conducted in English, French, and Korean languages. Patients/caregivers and health professionals completed a 9-point Likert scale (7-9 indicating critical importance) and a Best-Worst Scale. The absolute and relative importance of outcomes were assessed. Comments were analyzed thematically. 1,014 participants (603 [60%] patients/caregivers, 411 [40%] health professionals) from 56 countries completed round 1, and 713 (70%) completed round 2. The prioritized outcomes were kidney function (importance score, 8.6), end-stage kidney disease (8.6), death (7.9), blood pressure (7.9), kidney cystsize/growth (7.8), and cerebral aneurysm (7.7). Kidney cyst-related pain was the highest rated patient-reported outcome by both stakeholder groups. Seven themes explained the prioritization of outcomes: protecting lifeand health, directly encountering life-threatening and debilitating consequences, specificity to ADPKD, optimizing and extending quality of life, hidden suffering, destroying self-confidence, and lost opportunities. Study design precluded involvement from those without access to internet or limited computer literacy. Kidney function, end-stage kidney disease, and death were the most important outcomes to patients, caregivers, and health professionals. Kidney cyst-related pain was the highest rated patient-reported outcome. Consistent reporting of these top prioritized outcomes may strengthen the value of trials in ADPKD for decision making.