Hospitalization outcomes following planned versus unplanned dialysis initiation: a comparative study of hemodialysis and peritoneal dialysis modalities

Kidney replacement therapy (KRT) in end-stage kidney disease (ESKD) may be initiated either planned or unplanned. Planned initiation with established vascular or peritoneal access allows elective starts. In contrast, unplanned initiation often requires urgent-start dialysis, necessitating catheter placement and inpatient commencement, adversely affecting outcomes and healthcare utilization. This study compares hospitalization duration and total admissions between planned and unplanned dialysis initiations in hemodialysis (HD) and peritoneal dialysis (PD). The retrospective cohort included 502 ESKD patients who commenced dialysis between January 2022 and December 2024 at a tertiary hospital in Singapore. The primary outcome was hospitalization duration at dialysis initiation; secondary outcomes were kidney-related and all-cause admissions within six months. Logistic regression identified predictors of prolonged hospitalization (>12 days). Of 502 patients, 72.3% began dialysis unplanned. Median hospitalization was longer for unplanned than planned initiation (17 [IQR 9–30] versus 4 [1–11] days, p < 0.001). PD was associated with shorter hospitalization than HD in both planned (1 [1–3] versus 9.5 [7–18.3] days, p < 0.001) and unplanned (12 [1–34.5] versus 17 [10–30] days, p = 0.007) settings. In unadjusted comparisons, unplanned initiation was also associated with more kidney-related (p = 0.003) and all-cause (p < 0.001) admissions, although after adjustment only the association with all-cause admissions persisted. Independent predictors of prolonged hospitalization included unplanned initiation, older age, and crash-lander status; PD and Chinese ethnicity were protective. Our findings suggest that planned dialysis initiation may reduce both hospitalization duration and total admissions during the intermediate period of commencing KRT, whereas the benefit of PD was confined to a shorter index hospitalization.