REgistry of actiVE renAL rehabilitation in Japanese Dialysis patients (Reveal-D): A protocol for retrospective cohort study

Background Renal rehabilitation, particularly exercise therapy, plays a vital role in maintaining physical function and improving outcomes in patients undergoing hemodialysis. In April 2022, Japan introduced an insurance reimbursement policy for exercise instruction during hemodialysis. However, the clinical effectiveness and broader impact of this policy remain unclear. Objective This study aims to evaluate the impact of renal rehabilitation, especially exercise therapy during dialysis, on clinical outcomes, including mortality and hospitalization, in Japanese hemodialysis patients. It also assesses secondary outcomes such as frailty, physical function, and nutritional status. Methods A retrospective cohort study was conducted using data from 10 dialysis facilities across Japan between January 2021 and January 2024. Adult patients receiving outpatient hemodialysis were included. The exercise group received regular intradialytic exercise therapy, while a matched control group did not. Primary outcomes included death and hospitalization. Secondary outcomes included changes in physical function (e.g., grip strength, gait speed), serum albumin/creatinine levels, frailty scores, and care needs. Subgroup analyses were performed based on the presence of reimbursement claims for exercise instruction. Expected Results This multicenter study will provide the first large-scale evidence on the real-world impact of exercise therapy during hemodialysis following the 2022 reimbursement policy. It will also explore the association between exercise and improved physical, nutritional, and psychosocial outcomes. Conclusion The eventual findings from this study may clarify the role of structured exercise programs in dialysis care and have the potential to inform future health policy decisions in Japan and globally. These results could also help guide best practices in renal rehabilitation and optimize patient-oriented outcomes.