Prediction Model for eGFR Thresholds Guiding the Optimal Timing of Hemodialysis Preparation in Chronic Kidney Disease

Background/Objectives: The progression of chronic kidney disease (CKD) is influenced by multiple factors, complicating the determination of the optimal timing for hemodialysis preparation. The aim of this study was to identify predictive factors and develop a model to guide this timing in patients with CKD. Methods: This retrospective study included patients who progressed to end-stage kidney disease (ESKD) and initiated hemodialysis after at least one year of follow-up at a single tertiary hospital between January 2011 and June 2024. The estimated glomerular filtration rate at 6 months before hemodialysis initiation (eGFR_6M), indicating timing for vascular access creation, and its decline trajectory were retrospectively analyzed according to underlying diseases and clinical conditions. A regression model was developed, and its performance was evaluated in internal and external validation cohorts. Results: Among 507 patients, the mean eGFR_6M was 11.7 ± 4.9 mL/min/1.73 m², with higher values observed in patients with diabetes mellitus (DM), cardiovascular disease (CVD), stroke, dementia, liver cirrhosis (LC), nephrotic-range proteinuria, or hypoalbuminemia. The mean eGFR_6M decline rate was 8.3 ± 9.6 mL/min/1.73 m²/year, with more rapid declines observed in patients with DM, LC, nephrotic range proteinuria, and hypoalbuminemia. The model was developed using significant predictors-sex, impaired mobility, DM, CVD, left ventricular ejection fraction, blood urea nitrogen, and phosphate levels-and showed acceptable performance in both validation cohorts, with P30 ranging from 70% to 75%. Conclusions: This study provides nephrologists with an objective reference to guide the timing of dialysis preparation, supporting personalized ESKD life planning and improving patient outcomes.