Social disparities in the prevalence of diabetes in Australia and in the development of end stage renal disease due to diabetes for Aboriginal and Torres Strait Islanders in Australia and Maori and Pacific Islanders in New Zealand.

BACKGROUND: Disparities in health status occur between people with differing socioeconomic status and disadvantaged groups usually have the highest risk exposure and the worst health outcome. We sought to examine the social disparities in the population prevalence of diabetes and in the development of treated end stage renal disease due to type 1 diabetes which has not previously been studied in Australia and New Zealand in isolation from type 2 diabetes. METHODS: This observational study examined the population prevalence of diabetes in a sample of the Australian population (7,434,492) using data from the National Diabetes Services Scheme and of treated end stage renal disease due to diabetes using data from the Australian and New Zealand Dialysis and Transplant Registry. The data were then correlated with the Australian Bureau of Statistics Socioeconomic Indexes for Areas for an examination of socioeconomic disparities. RESULTS: There is a social gradient in the prevalence of diabetes in Australia with disease incidence decreasing incrementally with increasing affluence (Spearman's rho = .765 p < 0.001). There is a higher risk of developing end stage renal disease due to type 1 diabetes for males with low socioeconomic status (RR 1.20; CI 1.002-1.459) in comparison to females with low socioeconomic status. In Australia and New Zealand Aboriginal and Torres Strait Islanders, Maori and Pacific Islanders appear to have a low risk of end stage renal disease due to type 1 diabetes but continue to carry a vastly disproportionate burden of end stage renal disease due to type 2 diabetes (RR 6.57 CI 6.04-7.14 & 6.48 CI 6.02-6.97 respectively p < 0.001) in comparison to other Australian and New Zealanders. CONCLUSION: Whilst low socioeconomic status is associated with a higher prevalence of diabetes the inverse social gradient seen in this study has not previously been reported. The social disparity seen in relation to treated end stage renal disease due to type 2 diabetes for Aboriginal and Torres Strait Islanders, Maori and Pacific Islanders has changed very little in the past 20 years. Addressing the increasing incidence of diabetes in Australia requires consideration of the underlying social determinants of health.

The impact of antecedent trauma exposure and mental health symptoms on the post-deployment mental health of Afghanistan-deployed Australian troops.

BACKGROUND: Both traumatic deployment experiences and antecedent traumas increase personnel's risk of developing PTSD and depression. However, only cross-sectional studies have assessed whether antecedent trauma moderates stress reactions to deployment experiences. This study prospectively examines whether antecedent trauma moderates the association between deployment trauma and post-deployment PTSD and depressive symptoms after accounting for antecedent mental health problems, in a large Australian Defence Force (ADF) sample. METHODS: In the ADF Middle East Area of Operations Prospective Study, currently-serving military personnel deployed to Afghanistan across 2010-2012 (n = 1122) completed self-reported measures at pre-deployment and post-deployment. RESULTS: Within multivariable regressions, associations between deployment trauma and PTSD and depressive symptoms at post-deployment were stronger for personnel with greater antecedent trauma. However, once adjusting for antecedent mental health problems, these significant interaction effects disappeared. Instead, deployment-related trauma and antecedent mental health problems showed direct associations with post-deployment mental health problems. Antecedent trauma was also indirectly associated with post-deployment mental health problems through antecedent mental health problems. Similar associations were seen with prior combat exposure as a moderator. LIMITATIONS: Antecedent and deployment trauma were reported retrospectively. Self-reports may also suffer from social desirability bias, especially at pre-deployment. CONCLUSIONS: Our main effects results support the pervasive and cumulative negative effect of trauma on military personnel, regardless of its source. While antecedent trauma does not amplify personnel's psychological response to deployment trauma, it is indirectly associated with increased post-deployment mental health problems. Antecedent mental health should be considered within pre-deployment prevention programs, and deployment-trauma within post-operational screening.

Residential Location and Kidney Transplant Outcomes in Indigenous Compared With Nonindigenous Australians.

BACKGROUND: Indigenous Australians experience significantly worse graft and patient outcomes after kidney transplantation compared with nonindigenous Australians. It is unclear whether rural versus urban residential location might contribute to this. METHODS: All adult patients from the Australia and New Zealand Dialysis and Transplant Registry who received a kidney transplant in Australia between January 1, 2000, and December 31, 2012, were investigated. Patients' residential location was classified as urban (major city + inner regional) or rural (outer regional - very remote) using the Australian Bureau of Statistics Remoteness Area Classification. RESULTS: Of 7826 kidney transplant recipients, 271 (3%) were indigenous. Sixty-three percent of indigenous Australians lived in rural locations compared with 10% of nonindigenous Australians (P < 0.001). In adjusted analyses, the hazards ratio for graft loss for Indigenous compared with non-Indigenous race was 1.59 (95% confidence interval [95% CI], 1.01-2.50; P = 0.046). Residential location was not associated with graft survival. Both indigenous race and residential location influenced patient survival, with an adjusted hazards ratio for death of 1.94 (95% CI, 1.23-3.05; P = 0.004) comparing indigenous with nonindigenous and 1.26 (95% CI, 1.01-1.58; P = 0.043) comparing rural with urban recipients. Five-year graft and patient survivals were 70% (95% CI, 60%-78%) and 69% (95% CI, 61%-76%) in rural indigenous recipients compared with 91% (95% CI, 90%-92%) and 92% (95% CI, 91%-93%) in urban nonindigenous recipients. CONCLUSIONS: Indigenous kidney transplant recipients experience worse patient and graft survival compared with nonindigenous recipients, whereas rural residential location is associated with patient but not graft survival. Of all groups, indigenous recipients residing in rural locations experienced the lowest 5-year graft and patient survivals.

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 Maori 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 Maori (61%) and Europeans (88%). No Pacific patients who lost their grafts were re-transplanted within 72 patient-years of follow-up, whereas 14% of Maori patients and 36% of European and Asian patients were retransplanted within five yr. Current programs to improve live and deceased donation within Maori and Pacific people and management of recurrent kidney disease are likely to reduce these disparities.

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.

Renal replacement therapy associated with lithium nephrotoxicity in Australia.

OBJECTIVE: To analyse the annual incidence of end-stage renal disease (ESRD) associated with lithium-induced nephropathy (LiN) in Australia. DESIGN, SETTING AND PARTICIPANTS: Retrospective cohort study of patients commencing renal replacement therapy (RRT) in Australia. We compared patients with LiN with all other RRT patients between 1 January 1991 and 31 December 2011, using Australia and New Zealand Dialysis and Transplant Registry data. MAIN OUTCOME MEASURES: Numbers and characteristics of incident RRT patients, primary kidney disease (LiN or other, based on clinical diagnosis). RESULTS: LiN contributed to 187 people in Australia commencing RRT between 1 January 1991 and 31 December 2011. The incidence rate increased from 0.14 cases/million population/year (95% CI, 0.06-0.22) in 1992-1996 to 0.78 (95% CI, 0.67-0.90) in 2007-2011. This increase is unlikely to be attributed solely to demographic changes in Australia. LiN patients were more likely than non-LiN patients to be women, to be white, to smoke, and to have a higher body mass index, but were less likely to have undergone renal biopsy. CONCLUSIONS: Rates of ESRD attributed to LiN are increasing rapidly. Currently accepted lithium dosages and duration of treatment might induce ESRD in a large cohort of patients. We encourage clinicians to exercise discretion when prescribing lithium, check renal function regularly, stop lithium if there is a deterioration in two consecutive readings, and consider substitution with other drugs.

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.

Pregnancy outcomes according to dialysis commencing before or after conception in women with ESRD.

BACKGROUND AND OBJECTIVES: Pregnancy in ESRD is rare and poses substantial risk for mother and baby. This study describes a large series of pregnancies in women undergoing long-term dialysis treatment and reviews maternal and fetal outcomes. Specifically, women who had conceived before and after starting long-term dialysis are compared. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENT: All pregnancies reported to the Australian and New Zealand Dialysis and Transplantation Registry from 2001 to 2011 (n=77), following the introduction of specific parenthood data collection, were analyzed. RESULTS: Between 2001 and 2011, there were 77 pregnancies among 73 women. Of these, 53 pregnancies were in women who conceived after long-term dialysis was established and 24 pregnancies occurred before dialysis began. The overall live birth rate (after exclusion of elective terminations) was 73%. In pregnancies reaching 20 weeks gestation, the live birth rate was 82%. Women who conceived before dialysis commenced had significantly higher live birth rates (91% versus 63%; P=0.03), but infants had similar birthweight and gestational age. This difference in live birth rate was primarily due to higher rates of early pregnancy loss before 20 weeks in women who conceived after dialysis was established. In pregnancies that reached 20 weeks or more, the live birth rate was higher in women with conception before dialysis commenced (91% versus 76%; P=0.28). Overall, the median gestational age was 33.8 weeks (interquartile range, 30.6-37.6 weeks) and median birthweight was 1750 g (interquartile range, 1130-2417 g). More than 40% of pregnancies reached >34 weeks' gestation; prematurity at <28 weeks was 11.4% and 28-day neonatal survival rate was 98%. CONCLUSIONS: Women with kidney disease who start long-term dialysis after conception have superior live birth rates compared with those already established on dialysis at the time of conception, although these pregnancies remain high risk.

Racial disparities in paediatric kidney transplantation.

BACKGROUND: Transplantation is the preferred treatment for children with end-stage kidney disease (ESKD). Pre-emptive transplants, those from live donors and with few human leukocyte antigen (HLA) mismatches provide the best outcomes. Studies into disparities in paediatric transplantation to date have not adequately disentangled different transplant types. METHODS: We studied a retrospective cohort of 823 patients aged <18 years who started renal replacement therapy (RRT) in Australia 1990-2011, using the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA). The primary outcomes were time to first kidney transplant and kidney donor type (deceased or living), analysed using competing risk regression. RESULTS: Caucasian patients were most likely to receive any transplant, due largely to disparities in live donor transplantation. No Indigenous patients received a pre-emptive transplant. Indigenous patients were least likely to receive a transplant from a live donor (sub-hazard ratio 0.41, 95 % confidence interval 0.20-0.82, compared to Caucasians). Caucasian recipients had fewer HLA mismatches, were less sensitised and were more likely to have kidney diseases that could be diagnosed early or progress slowly. CONCLUSIONS: Caucasian paediatric patients are more likely to receive optimum treatment--a transplant from a living donor and fewer HLA mismatches. Further work is required to identify and address barriers to live donor transplantation among minority racial groups.

Peritoneal dialysis in rural Australia.

BACKGROUND: Australians 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. METHODS: Non-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). RESULTS: A 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). CONCLUSIONS: PD 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.

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.

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.

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. METHODS: We analysed a retrospective cohort of 508 adult patients who received primary kidney grafts at a single centre in South Australia, 2002-2009, using hospital records and Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data. Complications within 1 year of transplantation were classified into: surgical, wound, urological, delayed graft function, early nephrectomy and admission to intensive care unit (ICU). RESULTS: Overall, 62% of transplant recipients had a BMI above 25 kg/m(2) at transplant. Higher BMI was associated with an increased risk of wound complications (P < 0.001), early nephrectomy (P = 0.002) and delayed graft function (P = 0.03), but not associated with surgical or urological complications, or ICU admission. These associations were stronger for Indigenous Australians than other patients, especially for surgical complications. There was no BMI value above which risks of complications increase substantially. CONCLUSION: Delayed graft function is an important determinant of patient outcomes. Wound complications can be serious, and are more common in patients with higher BMI. This may justify the use of elevated BMI as a contraindication for transplantation, although no obvious cut-off value exists. Investigations into other measures of body fat composition and distribution are warranted.

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. METHODS: Data from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA)registry and relevant population data were used to investigate the incidence of RRT in five demographic groups: Indigenous and non-indigenous Australians, Maori, Pacific Islanders and other New Zealanders, as well as differences between genders and age groups. RESULTS: The numbers of patients commencing RRT each year increased by 321% between 1990 and 2009. This increase was largely driven by increases in patients with diabetic nephropathy. In 2009 35% of new patients had ESKD resulting from diabetic nephropathy 92% of which were type 2. Indigenous Australians, and Maori and Pacific people of NZ have elevated risks of commencing RRT due to diabetic nephropathy, although the risks compared with non-indigenous Australians have decreased over time. A small element of lead time bias also contributed to this increase. Males are more likely to commence RRT due to diabetes than females, except among Australian Aborigines, where females are more at risk. There is a marked increase in older, more comorbid patients. CONCLUSIONS: Patterns of incident renal replacement therapy strongly reflect the prevalence of diabetes within these groups. In addition, other factors such as reduced risk of dying before reaching ESKD, and increased acceptance of older and sicker patients are also contributing to increases in incidence of RRT.