An international Delphi survey helped develop consensus-based core outcome domains for trials in peritoneal dialysis

Shared decision-making about clinical care options in end-stage kidney disease is limited by inconsistencies in the reporting of outcomes and the omission of patient-important outcomes in trials. Here we generated a consensus-based prioritized list of outcomes to be reported during trials in peritoneal dialysis (PD). In an international, online, three-round Delphi survey, patients/caregivers and health professionals rated the importance of outcomes using a 9-point Likert scale (with 7-9 indicating critical importance) and provided comments. Using a Best-Worst Scale (BWS), the relative importance of outcomes was estimated. Comments were analyzed thematically. In total, 873 participants (207 patients/caregivers and 666 health professionals) from 68 countries completed round one, 629 completed round two and 530 completed round three. The top outcomes were PD-related infection, membrane function, peritoneal dialysis failure, cardiovascular disease, death, catheter complications, and the ability to do usual activities. Compared with health professionals, patients/caregivers gave higher priority to six outcomes: blood pressure (mean difference, 0.4), fatigue (0.3), membrane function (0.3), impact on family/friends (0.1), peritoneal thickening (0.1) and usual activities (0.1). Four themes were identified that underpinned the reasons for ratings: contributing to treatment longevity, preserving quality of life, escalating morbidity, and irrelevant and futile information and treatment. Patients/caregivers and health professionals gave highest priority to clinical outcomes. In contrast to health professionals, patients/caregivers gave higher priority to lifestyle-related outcomes including the impact on family/friends and usual activities. Thus, prioritization will inform a core outcome set to improve the consistency and relevance of outcomes for trials in PD.