# Health disparities in transitions between kidney replacement therapy modalities and mortality in England: A multistate model using UK Renal Registry data

## TL;DR

The study finds ethnic and deprivation-related health disparities in kidney treatment transitions and mortality in England, highlighting unequal access to home dialysis and transplantation over time.

## Contribution

This study introduces a multistate modeling approach to track health disparities in transitions between kidney replacement therapies and mortality across the patient life course.

## Key findings

- Asian and Black patients had lower transition rates to home dialysis and higher rates of returning to in-centre dialysis after transplantation.
- Patients in the most deprived areas had reduced access to home therapies and transplantation, with higher mortality and return rates to in-centre dialysis.
- The findings reveal persistent inequalities in kidney care pathways, emphasizing the need for equity-focused interventions.

## Abstract

While ethnic and deprivation-related disparities in kidney replacement therapy (KRT) initiation are well established, their impact on transitions between treatment modalities and mortality over the course of kidney failure remains poorly understood. This study aimed to examine the association between ethnicity and area-level deprivation and the rates of transition between treatment modalities and death across the patient life course on KRT.

We used a parametric multistate model to analyse UK Renal Registry data from 93,451 patients initiating KRT in England between 2005 and 2020 with a median follow-up of 1,497 days [IQR: 640−2,841] (4.1 years [IQR: 1.75,7.8]). We estimated transition-specific hazard rates and probabilities between peritoneal dialysis (PD), home haemodialysis (HHD), in-centre haemodialysis (ICHD), transplantation, and death using Weibull proportional hazard models. Ethnicity and area-level deprivation (measured by quintiles of the Index of Multiple Deprivation [IMD]) were included as covariates of primary interest, with models additionally adjusted for sex, age and diabetes mellitus as the primary kidney disease (PKD). Compared with White patients, Asian patients had lower transition rates from ICHD to PD (hazard ratio [HR]: 0.68, 95% confidence interval [CI] [0.51,0.91]), and from PD to ICHD (HR 0.85, 95% CI [0.78,0.92]), but a higher rate of returning to ICHD after transplantation (HR 1.12, 95% CI [1.01,1.24]). Black patients also had lower transition rates from ICHD to PD (HR 0.64, 95% CI [0.47,0.88]) and to HHD (HR 0.47, 95% CI [0.37,0.61]), but higher rates of transition from PD to ICHD (HR 1.16, 95% CI [1.01,1.33]) and from transplantation to ICHD (HR 1.73, 95% CI [1.44,2.08]). Patients living in the most deprived areas had lower transition rates from ICHD to PD (HR 0.63, 95% CI [0.56,0.70]), to HHD (HR 0.49, 95% CI [0.38,0.64]), and to transplantation (HR 0.57, 95% CI [0.52,0.64]), and higher rates from transplantation to ICHD (HR 1.63, 95% CI [1.43,1.85]) and to death (HR 1.53, 95% CI [1.33,1.76]), compared with those from the least deprived areas. A limitation of our study is that, apart from diabetes mellitus as the PKD, comorbidities were not included in the analysis due to incomplete reporting in the UK Renal Registry. This should be considered when interpreting the observed disparities, particularly those related to area-level deprivation.

These findings highlight persistent inequalities throughout the KRT pathway. The multistate modelling framework applied in this study offers a foundation for future research to design and evaluate interventions that improve equity and patient outcomes in kidney care.

Kidney replacement therapy (KRT) options such as home dialysis and transplantation can improve quality of life, but not everyone has equal access to these treatments.

Previous research has shown differences in who begins KRT, but much less is known about how these differences develop as patients move through different treatment stages over time.

We wanted to examine how these disparities unfold over the full course of KRT by using national data and a statistical model that tracks how people move from one treatment to another over time.

We analysed data from more than 93,000 adults in England who started KRT between 2005 and 2020. We estimated how people from different ethnic groups and living in areas with varying deprivation moved between treatment types or died.

Asian and Black patients experienced less favourable transition patterns compared to White patients, with lower rates of moving to home therapies and higher rates of returning to hospital dialysis after a transplant.

People living in the most deprived areas also faced barriers to accessing different treatment options. They had higher death rates and were more likely to return to in-centre haemodialysis.

Inequalities appear throughout the KRT pathway and are associated with differences in who accesses home-based therapies or transplantation, and in who faces higher risks of death or returning to hospital-based treatment.

The study identifies when and where these disparities occur, helping to identify critical points in the care pathway where equity-focussed interventions are most needed.

The transition estimates produced by this study can support the design and evaluation of policy and service changes to improve outcomes and reduce disparities in kidney care.

A limitation of the study is that information on health conditions other than diabetes (when diabetes was recorded as the main cause of kidney disease) was incomplete and therefore not included. This should be considered when interpreting the observed transition patterns, because having multiple health conditions may differ across groups and may affect treatment access and outcomes.

In an observational study, Jessica Potts and colleagues investigate health inequalities associated with the transitions in kidney therapy modality or death in the UK Renal Registry.Image: https://pixabay.com/illustrations/inequality-hierarchy-shadow-9923512/Credit: Pixabay AI generated