Transitions in an integrated model of renal replacement therapy in a regional health system

Introduction and objectives: The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

Material and methods: The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1^st RRT modality and as-treated (AT) analysis, that consider also their 1^st transition.

Results: A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KTX). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p<0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs 8.3% KTX group, p<0.001) and less access to a transplant (HD group 30.4% vs DP group 51.6%; p<0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD→PD: 0.7 years (SD 1.1) vs PD→HD: 1.5 years (SD 1.4) p<0.001), are younger (HD→PD: 53.5 years (SD 16.7) vs PD→HD: 61.6 years (SD 14.6); p<0.001), presented less mortality (HD→PD: 24.5% vs PD→HD: 32.0%; p<0.001) and higher access to a transplant (HD→PD: 49.4% vs PD→HD: 31.7%; p<0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

Conclusion: Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.