Blair S. Grace

Increases in renal replacement therapy in Australia and New Zealand: Understanding trends in diabetic nephropathy

Aim:  The incidence of end‐stage kidney disease (ESKD) has been increasing worldwide, with increasing numbers of older people, people with diabetic nephropathy and indigenous people. We investigated the incidence of renal replacement therapy (RRT) in Australia and New Zealand (NZ) to better understand the causes of these effects.

Transplantation rates for living- but not deceased-donor kidneys vary with socioeconomic status in Australia.

Socioeconomic disadvantage has been linked to reduced access to kidney transplantation. To understand and address potential barriers to transplantation, we used the Australia and New Zealand Dialysis and Transplant Registry and examined primary kidney-only transplantation among adult non-Indigenous patients who commenced chronic renal replacement therapy in Australia during 2000-2010. Socioeconomic status was derived from residential postcodes using standard indices. Among the 21,190 patients who commenced renal replacement therapy, 4105 received a kidney transplant (2058 from living donors (660 preemptive) or 2047 from deceased donors) by the end of 2010. Compared with the most socioeconomic disadvantaged quartile, patients from the most advantaged quartile were more likely to receive a preemptive transplant (relative rate 1.93), and more likely to receive a living-donor kidney (adjusted subhazard ratio 1.34) after commencing dialysis. Socioeconomic status was not associated with deceased-donor transplantation. Thus, the association between socioeconomic status and living- but not deceased-donor transplantation suggests that potential donors (rather than recipients) from disadvantaged areas may face barriers to donation. Although the deceased-donor organ allocation process appears essentially equitable, it differs between Australian states.

The immune phenotype may relate to cancer development in kidney transplant recipients.

High regulatory T-cell (Treg) numbers predict recurrent cutaneous squamous cell carcinoma in kidney transplant recipients, and the Treg immune phenotype may identify kidney transplant recipients at risk of developing squamous cell carcinoma and/or solid-organ cancer. To investigate this, a total of 116 kidney transplant recipients, of whom 65 had current or past cancer, were immune-phenotyped and followed up prospectively for a median of 15 months. Higher Treg (CD3+CD4+FOXP3+CD25(Hi)CD127(Lo)) proportion and numbers significantly increased the odds of developing cancer (odds ratios (95% CI) 1.61 (1.17-2.20) and 1.03 (1.00-1.06), respectively) after adjusting for age, gender, and duration of immunosuppression. Class-switched memory B cells (CD19+CD27+IgD-) had a significant association to cancer, 1.04 (1.00-1.07). Receiver operator characteristic (ROC) curves for squamous cell carcinoma development within 100 days of immune phenotyping were significant for Tregs, memory B cells, and γδ T cells (AUC of 0.78, 0.68, and 0.65, respectively). After cancer resection, Treg, NK cell, and γδ T-cell numbers fell significantly. Immune-phenotype profiles associated with both squamous cell carcinoma and solid-organ cancer in kidney transplant recipients and depended on the presence of cancer tissue. Thus, immune profiling could be used to stratify kidney transplant recipients at risk of developing cancers to identify those who could qualify for prevention therapy.

Socio-economic status and incidence of renal replacement therapy: a registry study of Australian patients

BACKGROUND Socio-economic disadvantage has been linked to higher incidence of end-stage kidney disease in developed countries. Associations between socio-economic status (SES) and incidence of renal replacement therapy (RRT) have not been explored for different kidney diseases, genders or age groups in a country with universal access to healthcare. METHODS We investigated the incidence of non-indigenous patients commencing RRT in Australia in 2000-09, using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Patient postcodes were grouped into deciles using a standard SES index. We analysed incidence by five groups of kidney diseases, age groups, gender and geographic remoteness. RESULTS Incidence of RRT decreased with increasing area advantage. Differences were most evident for the most disadvantaged areas [markedly increased burden; incident rate ratio (IRR) 1.27; 95% confidence interval (CI) 1.18-1.38] and most advantaged decile (decreased burden, IRR 0.76; 95% CI 0.72-0.81), compared with decile 5. Patients with diabetic nephropathy showed the greatest disparities: residents of the most disadvantaged decile were 2.38 (95% CI 2.09-2.71) times more at risk than the most advantaged decile. Congenital and genetic kidney diseases showed lesser gradients-the most disadvantaged decile was 1.28 times (95% CI 0.98-1.68) more at risk. SES was not associated with incidence for patients older than 69 years. DISCUSSION These SES gradients existed, despite all Australians having access to healthcare. Diseases associated with lifestyle show the greatest gradients with SES.

Body mass index and postoperative complications in kidney transplant recipients

Background:  There is a growing number of overweight and obese patients receiving kidney transplants, despite elevated body mass index (BMI) being associated with postoperative complications. Understanding associations between BMI and complications would allow more objectivity when recommending patients for transplantation or otherwise.

Socioeconomic differences in the uptake of home dialysis

BACKGROUND AND OBJECTIVES Home dialysis creates fewer lifestyle disruptions while providing similar or better outcomes than in-center hemodialysis. Socioeconomically advantaged patients are more likely to commence home dialysis (peritoneal dialysis and home hemodialysis) in many developed countries. This study investigated associations between socioeconomic status and uptake of home dialysis in Australia, a country with universal access to health care and comparatively high rates of home dialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study analyzed 23,281 non-Indigenous adult patients who commenced chronic RRT in Australia from 2000 to 2011 according to the Australia and New Zealand Dialysis and Transplant Registry in a retrospective cohort study. This study investigated the proportion of patients who were ever likely to use home dialysis using nonmixture cure models and followed patients until the end of 2011 (median follow-up time=3.0 years, interquartile range=1.3-5.5 years). The main predictor was area socioeconomic status from postcodes grouped into quartiles using standard indices. RESULTS Patients from the most advantaged quartile of areas were less likely to commence peritoneal dialysis (odds ratio, 0.63; 95% confidence interval, 0.58 to 0.69) and more likely to use in-center hemodialysis than patients from the most disadvantaged areas (odds ratio, 1.19; 95% confidence interval, 1.10 to 1.30). Socioeconomic status was not associated with uptake of home hemodialysis. Rural areas were more disadvantaged and had higher rates of peritoneal dialysis, and privately funded hospitals rarely used home dialysis. Patients from the most advantaged quartile of areas were more likely to use private hospitals than patients from the most disadvantaged quartile (odds ratio, 5.9; 95% confidence interval, 4.6 to 7.5). CONCLUSION The lower incidence of peritoneal dialysis among patients from advantaged areas seems to be multifactorial. Identifying and addressing barriers to home dialysis in Australia could improve patient quality of life and reduce costs.

Peritoneal dialysis in rural Australia

BackgroundAustralians living in rural areas have lower incidence rates of renal replacement therapy and poorer dialysis survival compared with urban dwellers. This study compares peritoneal dialysis (PD) patient characteristics and outcomes in rural and urban Australia.MethodsNon-indigenous Australian adults who commenced chronic dialysis between 1 January 2000 and 31 December 2010 according to the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) were investigated. Each patient’s residence was classified according to the Australian Bureau of Statistics remote area index as major city (MC), inner regional (IR), outer regional (OR), or remote/very remote (REM).ResultsA total of 7657 patients underwent PD treatment during the study period. Patient distribution was 69.0% MC, 19.6% IR, 9.5% OR, and 1.8% REM. PD uptake increased with increasing remoteness. Compared with MC, sub-hazard ratios [95% confidence intervals] for commencing PD were 1.70 [1.61-1.79] IR, 2.01 [1.87-2.16] OR, and 2.60 [2.21-3.06] REM. During the first 6 months of PD, technique failure was less likely outside MC (sub-hazard ratio 0.47 [95% CI: 0.35-0.62], P < 0.001), but no difference was seen after 6 months (sub-hazard ratio 1.05 [95% CI: 0.84-1.32], P = 0.6). Technique failure due to technical (sub-hazard ratio 0.57 [95% CI: 0.38-0.84], P = 0.005) and non-medical causes (sub-hazard ratio 0.52 [95% CI: 0.31-0.87], P = 0.01) was less likely outside MC. Time to first peritonitis episode was not associated with remoteness (P = 0.8). Patient survival while on PD or within 90 days of stopping PD did not differ by region (P = 0.2).ConclusionsPD uptake increases with increasing remoteness. In rural areas, PD technique failure is less likely during the first 6 months and time to first peritonitis is comparable to urban areas. Mortality while on PD does not differ by region. PD is therefore a good dialysis modality choice for rural patients in Australia.

Racial disparities in pediatric kidney transplantation in New Zealand

Racial disparities in transplantation rates and outcomes have not been investigated in detail for NZ, a country with unique demographics. We studied a retrospective cohort of 215 patients <18 yr who started renal replacement therapy in NZ 1990–2012, using the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA). Primary outcomes were time to first kidney transplant, death‐censored graft survival, and retransplantation after loss of primary graft. Europeans and Asians were most likely to receive a transplant (92% and 91% transplanted within five yr, respectively), and Pacific and Māori patients were less likely to receive a transplant than Europeans (51% and 46%, respectively), reflecting disparities in live donor transplantation. Pacific patients were more likely to have glomerulonephritis and FSGS. Pacific patients had five‐yr death‐censored graft survival of 31%, lower than Māori (61%) and Europeans (88%). No Pacific patients who lost their grafts were re‐transplanted within 72 patient‐years of follow‐up, whereas 14% of Māori patients and 36% of European and Asian patients were retransplanted within five yr. Current programs to improve live and deceased donation within Māori and Pacific people and management of recurrent kidney disease are likely to reduce these disparities.

SOCIO-ECONOMIC STATUS AND PERITONITIS IN AUSTRALIAN NON-INDIGENOUS PERITONEAL DIALYSIS PATIENTS

♦ Background: The aim of the present study was to investigate the relationship between socio-economic status (SES) and peritoneal dialysis (PD)-related peritonitis. ♦ Methods: Associations between area SES and peritonitis risk and outcomes were examined in all non-indigenous patients who received PD in Australia between 1 October 2003 and 31 December 2010 (peritonitis outcomes). SES was assessed by deciles of postcode-based Australian Socio-Economic Indexes for Areas (SEIFA), including Index of Relative Socio-economic Disadvantage (IRSD), Index of Relative Socio-economic Advantage and Disadvantage (IRSAD), Index of Economic Resources (IER) and Index of Education and Occupation (IEO). ♦ Results: 7,417 patients were included in the present study. Mixed-effects Poisson regression demonstrated that incident rate ratios for peritonitis were generally lower in the higher SEIFA-based deciles compared with the reference (decile 1), although the reductions were only statistically significant in some deciles (IRSAD deciles 2 and 4 – 9; IRSD deciles 4 – 6; IER deciles 4 and 6; IEO deciles 3 and 6). Mixed-effects logistic regression showed that lower probabilities of hospitalization were predicted by relatively higher SES, and lower probabilities of peritonitis-associated death were predicted by less SES disadvantage status and greater access to economic resources. No association was observed between SES and the risks of peritonitis cure, catheter removal and permanent hemodialysis (HD) transfer. ♦ Conclusions: In Australia, where there is universal free healthcare, higher SES was associated with lower risks of peritonitis-associated hospitalization and death, and a lower risk of peritonitis in some categories.

Does equal care give equal outcomes

Kidney transplant recipients of lower socioeconomic status (SES) or from lower-SES areas have comparatively poor graft survival. Whether this results in poorer patient survival after kidney transplantation was largely unknown. Begaj et al. demonstrate that kidney transplant recipients from deprived areas have higher mortality than patients from more advantaged areas in England. We found similar patterns in Australia. If such disparities are to be addressed, a better understanding of the mediating factors is required.