The survival benefit of deceased donor kidney transplantation for Aboriginal and Torres Strait Islander people, 2006-20: a retrospective national cohort study.

OBJECTIVES: To quantify the survival benefit of kidney transplantation for Aboriginal and Torres Strait Islander people waitlisted for deceased donor kidney transplantation in Australia. STUDY DESIGN: Retrospective cohort study; analysis of linked data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry, the Australia and New Zealand Organ Donation (ANZOD) registry, and OrganMatch (Australian Red Cross). SETTING, PARTICIPANTS: All adult Aboriginal and Torres Strait Islander people (18 years or older) who commenced dialysis in Australia during 1 July 2006 - 31 December 2020 and were included in the kidney-only deceased donor transplant waiting list. MAIN OUTCOME MEASURES: Survival benefit of deceased donor kidney transplantation relative to remaining on dialysis. RESULTS: Of the 4082 Aboriginal and Torres Strait Islander people who commenced dialysis, 450 were waitlisted for kidney transplants (11%), of whom 323 received deceased donor transplants. Transplantation was associated with a significant survival benefit compared with remaining on dialysis after the first 12 months (adjusted hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.20-0.73). This benefit was similar to that for waitlisted non-Indigenous people who received deceased donor kidney transplants (adjusted HR, 0.47; 95% CI, 0.40-0.57; Indigenous status interaction: P = 0.22). CONCLUSIONS: From twelve months post-transplantation, deceased donor transplantation provides a survival benefit for Aboriginal and Torres Strait Islander people. Our findings provide evidence that supports efforts to promote the waitlisting of Aboriginal and Torres Strait Islander people who are otherwise eligible for transplantation.

Why surveys are 'very hard': exploring challenges and insights for collection of authentic patient experience information with speakers of Australian First Nations languages.

INTRODUCTION: Health services collect patient experience data to monitor, evaluate and improve services and subsequently health outcomes. Obtaining authentic patient experience information to inform improvements relies on the quality of data collection processes and the responsiveness of these processes to the cultural and linguistic needs of diverse populations. This study explores the challenges and considerations in collecting authentic patient experience information through survey methods with Australians who primarily speak First Nations languages. METHODS: First Nations language experts, interpreters, health staff and researchers with expertise in intercultural communication engaged in an iterative process of critical review of two survey tools using qualitative methods. These included a collaborative process of repeated translation and back translation of survey items and collaborative analysis of video-recorded trial administration of surveys with languages experts (who were also receiving dialysis treatment) and survey administrators. All research activities were audio- or video-recorded, and data from all sources were translated, transcribed and inductively analysed to identify key elements influencing acceptability and relevance of both survey process and items as well as translatability. RESULTS: Serious challenges in achieving equivalence of meaning between English and translated versions of survey items were pervasive. Translatability of original survey items was extensively compromised by the use of metaphors specific to the cultural context within which surveys were developed, English words that are familiar but used with different meaning, English terms with no equivalent in First Nations languages and grammatical discordance between languages. Discordance between survey methods and First Nations cultural protocols and preferences for seeking and sharing information was also important: the lack of opportunity to share the 'full story', discomfort with direct questions and communication protocols that preclude negative or critical responses constrained the authenticity of the information obtained through survey methods. These limitations have serious implications for the quality of information collected and result in frustration and distress for those engaging with the survey. CONCLUSION: Profound implications for the acceptability of a survey tool as well as data quality arise from differences between First Nations cultural and communication contexts and the cultural context within which survey methods have evolved. When data collection processes are not linguistically and culturally congruent there is a risk that patient experience data are inaccurate, miss what is important to First Nations patients and have limited utility for informing relevant healthcare improvement. Engagement of First Nations cultural and language experts is essential in all stages of development, implementation and evaluation of culturally safe and effective approaches to support speakers of First Nations languages to share their experiences of health care and influence change.

Risk of kidney disease following a pregnancy complicated by diabetes: a longitudinal, population-based data-linkage study among Aboriginal women in the Northern Territory, Australia.

AIMS/HYPOTHESIS: The aim of this work was to investigate the risk of developing chronic kidney disease (CKD) or end-stage kidney disease (ESKD) following a pregnancy complicated by gestational diabetes mellitus (GDM) or pre-existing diabetes among Aboriginal women in the Northern Territory (NT), Australia. METHODS: We undertook a longitudinal study of linked healthcare datasets. All Aboriginal women who gave birth between 2000 and 2016 were eligible for inclusion. Diabetes status in the index pregnancy was as recorded in the NT Perinatal Data Collection. Outcomes included any stage of CKD and ESKD as defined by ICD-10 coding in the NT Hospital Inpatient Activity dataset between 2000 and 2018. Risk was compared using Cox proportional hazards regression. RESULTS: Among 10,508 Aboriginal women, the mean age was 23.1 (SD 6.1) years; 731 (7.0%) had GDM and 239 (2.3%) had pre-existing diabetes in pregnancy. Median follow-up was 12.1 years. Compared with women with no diabetes during pregnancy, women with GDM had increased risk of CKD (9.2% vs 2.2%, adjusted HR 5.2 [95% CI 3.9, 7.1]) and ESKD (2.4% vs 0.4%, adjusted HR 10.8 [95% CI 5.6, 20.8]). Among women with pre-existing diabetes in pregnancy, 29.1% developed CKD (adjusted HR 10.9 [95% CI 7.7, 15.4]) and 9.9% developed ESKD (adjusted HR 28.0 [95% CI 13.4, 58.6]). CONCLUSIONS/INTERPRETATION: Aboriginal women in the NT with GDM or pre-existing diabetes during pregnancy are at high risk of developing CKD and ESKD. Pregnancy presents an important opportunity to identify kidney disease risk. Strategies to prevent kidney disease and address the social determinants of health are needed.

Electronic alerts and a care bundle for acute kidney injury-an Australian cohort study.

BACKGROUND: Early recognition of hospital-acquired acute kidney injury (AKI) may improve patient management and outcomes. METHODS: This multicentre study was conducted at three hospitals (H1-intervention; H2 and H3-controls) served by a single laboratory. The intervention bundle [an interruptive automated alerts (aAlerts) showing AKI stage and baseline creatinine in the eMR, a management guide and junior medical staff education] was implemented only at H1. Outcome variables included length-of-stay (LOS), all-cause in-hospital mortality and management quality. RESULTS: Over 6 months, 639 patients developed AKI (265 at H1 and 374 at controls), with 94.7% in general wards; 537 (84%) patients developed Stage 1, 58 (9%) Stage 2 and 43 (7%) Stage 3 AKI. Median LOS was 9 days (IQR 4-17) and was not different between intervention and controls. However, patients with AKI stage 1 had shorter LOS at H1 [median 8 versus 10 days (P = 0.021)]. Serum creatinine had risen prior to admission in most patients. Documentation of AKI was better in H1 (94.8% versus 83.4%; P = 0.001), with higher rates of nephrology consultation (25% versus 19%; P = 0.04) and cessation of nephrotoxins (25.3 versus 18.8%; P = 0.045). There was no difference in mortality between H1 versus controls (11.7% versus 13.0%; P = 0.71). CONCLUSIONS: Most hospitalized patients developed Stage 1 AKI and developed AKI in the community and remained outside the intensive care unit (ICU). The AKI eAlert bundle reduced LOS in most patients with AKI and increased AKI documentation, nephrology consultation rate and cessation of nephrotoxic medications.

Retrospective case-control study exploring pretransplant predictors for loss of kidney transplant function or death among indigenous kidney transplant recipients.

BACKGROUND: The factors affecting the outcomes among Indigenous kidney transplant recipients is not fully understood. We conducted a retrospective case control study to identify risk factors beyond those explained by the ANZDATA registry. AIM: To identify the risk factors for loss of kidney transplant function or death among Indigenous kidney transplant recipients. METHODS: Cases were defined as all Indigenous Australian kidney transplant recipients from 1 January 2005 to 31 December 2015 from the major hospitals in the Northern Territory (NT) and South Australia (SA) who experienced graft loss (including patient death) up to 2-years post-transplant. Controls (matched 4:1) were defined as all indigenous kidney transplant recipients during the same period with functioning transplants at 2-years post-transplant operation. Matching was done on gender and diabetes status. Regression analysis adjusted for age was used for comparing cases and controls. RESULTS: There were 17 cases and 68 matched controls. Among cases, the odds ratio for more than one hospital admission episode (compared with ≤1 episode) in the 2-year pretransplant period was 6.2 (95% confidence interval, 1.2-32.5). However, there were no significant differences in the frequency of comorbidities at renal replacement therapy start, cardiovascular intervention pretransplant, pretransplant infection screening, age and gender of the donors, frequency of admission episodes where an infection was documented, the total length of inpatient stay or admission to intensive care unit during pretransplant hospital admission between cases and controls. CONCLUSION: Early graft loss was associated with a higher frequency of hospital admissions in the 2-years pretransplant period. In contrast, other measured factors in the pretransplant period did not predict these adverse outcomes.

Comparison of two ferritin assay platforms to assess their level of agreement in measuring serum and plasma ferritin levels in patients with chronic kidney disease.

BACKGROUND: Ferritin levels are used to make decisions on therapy of iron deficiency in patients with chronic kidney disease (CKD). Hyperferritinaemia, common among patients with CKD from the Northern Territory (NT) of Australia, makes use of ferritin levels as per clinical guidelines challenging. No gold standard assay exists for measuring ferritin levels. Significant variability between results from different assays creates challenges for clinical decision-making regarding iron therapy. In the NT, different laboratories use different methods. In 2018, Territory Pathology changed the assay from Abbott ARCHITECT i1000 (AA) to Ortho-Clinical Diagnostics Vitros 7600 (OCD). This was during the planning of the INtravenous iron polymaltose for First Nations Australian patients with high FERRitin levels on haemodialysis (INFERR) clinical trial. The trial design was based on AA assay ferritin levels. We compared the two assays' level of agreement in measuring ferritin levels in CKD patients. METHODS: Samples from INFERR clinical trial participants were analysed. Other samples from patients whose testing were completed the same day on OCD analyzers and run within 24 h on AA analyzers were added to ensure wide range of ferritin levels, adding statistical strength to the comparison. Ferritin levels from both assays were compared using Pearson's correlation, Bland-Altman, Deming and Passing-Bablok regression analyses. Differences between sample types, plasma and serum were assessed. RESULTS: Sixty-eight and 111 (179) samples from different patients from Central Australia and Top End of Australia, respectively, were analyzed separately and in combination. The ferritin levels ranged from 3.1 µg/L to 3354 µg/L and 3 µg/L to 2170 µg/L for AA and OCD assays respectively. Using Bland-Altman, Deming and Passing-Bablok regression methods for comparison, ferritin results were consistently 36% to 44% higher with AA than OCD assays. The bias was up to 49%. AA ferritin results were the same in serum and plasma. However, OCD ferritin results were 5% higher in serum than plasma. CONCLUSIONS: When making clinical decisions, using ferritin results from the same assay in patients with CKD is critical. If the assay is changed, it is essential to assess agreement between results from the new and old assays. Further studies to harmonize ferritin assays are required.

Dialysis attendance patterns and health care utilisation of Aboriginal patients attending dialysis services in urban, rural and remote locations.

BACKGROUND: Aboriginal people in the Northern Territory (NT) suffer the heaviest burden of kidney failure in Australia with most living in remote areas at time of dialysis commencement. As there are few dialysis services in remote areas, many Aboriginal people are required to relocate often permanently, to access treatment. Missing dialysis treatments is not uncommon amongst Aboriginal patients but the relationship between location of dialysis service and dialysis attendance (and subsequent hospital use) has not been explored to date. AIM: To examine the relationships between location of dialysis service, dialysis attendance patterns and downstream health service use (overnight hospital admissions, emergency department presentations) among Aboriginal patients in the NT. METHODS: Using linked hospital and dialysis registry datasets we analysed health service activity for 896 Aboriginal maintenance dialysis patients in the NT between 2008 and 2014. Multivariate linear regression and negative binomial regression analyses explored the associations between dialysis location, dialysis attendance and health service use. RESULTS: We found missing two or more dialysis treatments per month was more likely for Aboriginal people attending urban services and this was associated with a two-fold increase in the rate of hospital admissions and more than three-fold increase in ED presentations. However, we found higher dialysis attendance and lower health service utilisation for those receiving care in rural and remote settings. When adjusted for age, time on dialysis, region, comorbidities and residence pre-treatment, among Aboriginal people from remote areas, those dialysing in remote areas had lower rates of hospitalisations (IRR 0.56; P < 0.001) when compared to those who relocated and dialysed in urban areas. CONCLUSION: There is a clear relationship between the provision and uptake of dialysis services in urban, rural and remote areas in the NT and subsequent broader health service utilisation. Our study suggests that the low dialysis attendance associated with relocation and care in urban models for Aboriginal people can potentially be ameliorated by access to rural and remote models and this warrants a rethinking of service delivery policy. If providers are to deliver effective and equitable services, the full range of intended and unintended consequences of a dialysis location should be incorporated into planning decisions.

Do remote dialysis services really cost more? An economic analysis of hospital and dialysis modality costs associated with dialysis services in urban, rural and remote settings.

BACKGROUND: Rates of end-stage kidney disease in Australia are highest in the Northern Territory (NT), with the burden of disease heaviest in remote areas. However, the high cost of delivering dialysis services in remote areas has resulted in centralisation, requiring many people to relocate for treatment. Patients argue that treatment closer to home improves health outcomes and reduces downstream healthcare use. Existing dialysis cost studies have not compared total health care costs associated with treatment in different locations. OBJECTIVE: To estimate and compare, from a payer perspective, the observed health service costs (all cause hospital admissions, emergency department presentations and maintenance dialysis) associated with different dialysis models in urban, rural and remote locations. METHODS: Using cost weights attributed to diagnostic codes in the NT Department of Health's hospital admission data set (2008-2014), we calculated the mean (SD) total annual health service costs by dialysis model for 995 dialysis patients. Generalized linear modeling with bootstrapping tested the marginal cost differences between different explanatory variables to estimate 'best casemix'/'worst casemix' cost scenarios. RESULTS: The mean annual patient hospital expenditure was highest for urban models at $97 928 (SD $21 261) and $43 440 (SD $5 048) and lowest for remote at $19 584 (SD $4 394). When combined with the observed maintenance dialysis costs, expenditure was the highest for urban models at $148 510 (SD $19 774). The incremental cost increase of dialysing in an urban area, compared with a rural area, for a relocated person from a remote area, was $5 648 more and increased further for those from remote and very remote areas to $10 785 and $15 118 respectively. CONCLUSIONS: This study demonstrates that dialysis treatment in urban areas for relocated people has health and cost implications that maybe greater than the cost of remote service delivery. The study emphasises the importance of considering all health service costs and cost consequences of service delivery models. KEY POINTS FOR DECISION MAKERS: Relocation for dialysis treatment has serious health and economic consequences. Relocated people have low dialysis attendance and high hospital costs in urban areas. While remote dialysis service models are more expensive than urban models, the comparative cost differences are significantly reduced when all health service costs are included. The delivery of equitable and accessible dialysis service models requires a holistic approach that incorporates the needs of the patient; hence dialysis cost studies must consider the full range of cost impacts beyond the dialysis treatments alone.

Most people requiring ongoing treatment for end-stage kidney disease in the Northern Territory (NT) identify as Aboriginal with the majority residing in areas classified as remote or very remote. Unlike other jurisdictions in Australia, haemodialysis in a satellite unit is the most common form of treatment. However, there is a geographic mismatch between demand and service provision, with services centralised in urban areas. Patients and communities have long advocated for services at or closer to home, maintaining that the consequences of relocation and dislocation have far reaching health, psychosocial and economic ramifications. We analysed retrospective hospital data for 995 maintenance dialysis patients, stratified by the model of care they received in urban, rural and remote locations. Using cost weights attributed to diagnosis codes, we costed hospital admissions, emergency department presentations and maintenance dialysis attendances, to provide a mean total health service cost/patient/year for each model of care. We found that urban services were associated with low observed maintenance dialysis and high hospital costs, but the inverse was true for remote and very remote models. Remote models had high maintenance dialysis costs (due to expense of remote service delivery and good dialysis attendance) but low hospital usage and costs. When adjusted for other variables such as age, dialysis vintage and comorbidities, lower total hospital costs were associated with rural and remote service provision. In an environment of escalating demand and constrained budgets, this study underlines the need for policy decisions to consider the full cost consequences of different dialysis service models.

Socioeconomic status and dialysis quality of care.

AIM: Lower socioeconomic status (SES) has been associated with increased dialysis mortality. This study aimed to determine if the quality of care (QOC) delivered to dialysis patients varied by SES. METHODS: All non-Indigenous adults commencing haemodialysis (HD) or peritoneal dialysis (PD) registered with the Australia and New Zealand Dialysis and Transplant Registry between 2002 and 2012 were included. Each patient's location at dialysis start was classified into SES quartiles of advantaged to disadvantaged. Guidelines were used to determine attainment of adequate QOC at 6-<18 months and 18-<30 months after dialysis start, using logistic regression models. QOC measures included pre-dialysis phosphate, calcium, haemoglobin, transferrin saturation and ferritin. HD-related parameters included single pool Kt/V and percentage with functioning arteriovenous fistula/graft. PD-related parameters included weekly Kt/V and percentage transferring to HD. RESULTS: Of 19 486 commencing dialysis, the median age was 65 years (interquartile range 53-74), 62.2% were male and 85.1% were Caucasian. At 6-<18 months after dialysis start, there were no significant differences by SES in attainment of biochemical targets, PD or HD adequacy. The disadvantaged quartile was less likely to achieve haemoglobin targets (odds ratio 0.88, 0.80-0.96, P = 0.01) or have a functioning arteriovenous fistula or graft (odds ratio 0.79, 0.68-0.92, P = 0.003) compared with the most advantaged group. Vascular access differences persisted at 18-<30 months. CONCLUSION: Other than vascular access, area-level SES has minimal impact on QOC attainment among non-Indigenous dialysis patients in Australia. Increased mortality in lower SES groups may be due to pre-dialysis factors and other variables such as health-related behaviours, lifestyle and literacy.

Chronic kidney disease and socio-economic status: a cross sectional study.

Objective: This cross-sectional study investigated the relationship between individual-level markers of disadvantage, renal function and cardio-metabolic risk within an Indigenous population characterised by a heavy burden of chronic kidney disease and disadvantage.Design: Using data from 20 Indigenous communities across Australia, an aggregate socio-economic status (SES) score was created from individual-level socio-economic variables reported by participants. Logistic regression was used to assess the association of individual-level socio-economic variables and the SES score with kidney function (an estimated glomerular function rate (eGFR) cut-point of <60 ml/min/1.73 m2) as well as clinical indicators of cardio-metabolic risk.Results: The combination of lower education and unemployment was associated with poorer kidney function and higher cardio-metabolic risk factors. Regression models adjusted for age and gender showed that an eGFR < 60 ml/min/1.73 m2 was associated with a low socio-economic score (lowest vs. highest 3.24 [95% CI 1.43-6.97]), remote living (remote vs. highly to moderately accessible 3.24 [95% CI 1.28-8.23]), renting (renting vs. owning/being purchased 5.76[95% CI 1.91-17.33]), unemployment (unemployed vs employed 2.85 [95% CI 1.31-6.19]) and receiving welfare (welfare vs. salary 2.49 [95% CI 1.42-4.37]). A higher aggregate socio-economic score was inversely associated with an eGFR < 60 ml/min/1.73 m2 (0.75 [95% CI 063-0.89]).Conclusion: This study extends upon our understanding of associations between area-level markers of disadvantage and burden of end stage kidney disease amongst Indigenous populations to a detailed analysis of a range of well-characterised individual-level factors such as overall low socio-economic status, remote living, renting, unemployment and welfare. With the increasing burden of end-stage kidney disease amongst Indigenous people, the underlying socio-economic conditions and social and cultural determinants of health need to be understood at an individual as well as community-level, to develop, implement, target and sustain interventions.

Does delay in planned diabetes care influence outcomes for aboriginal Australians? A study of quality in health care.

BACKGROUND: To examine the association between delay in planned diabetes care and quality of outcomes. METHODS: A retrospective analysis of primary care and inpatient records for 2567 Aboriginal patients, with diabetes, living in 49 remote communities in the Northern Territory of Australia. Poisson regression was used to estimate the association between delay from diagnosis to documented diabetes care plan and three outcome measures: mean HbA1c level, most recent blood pressure and number of diabetes-related hospital admissions. RESULTS: Compared with no delay (< 60 days), patients with delay had increased risk of elevated mean HbA1c: 60 days to < 2 years, incidence rate ratio (IRR), 1.2 (95% CI:1.07-1.39); 2 years to < 4 years, incidence rate ratio (IRR), 1.2 (95% CI:1.04-1.45); 4 years and over, incidence rate ratio (IRR), 1.3 (95% CI:1.12-1.52). There was no evidence of association between delay and optimal blood pressure control. Risk of diabetes-related admission increased with increased delay. Compared with no delay the IRRs for delay were: 60 days to < 2 years, 1.2 (95% CI:1.07-1.42); 2 to < 4 years, 1.3 (95% CI: 1.15-1.58): and 4 years and over, 2.6 (95% CI,2.28-3.08). CONCLUSION: The study found that a timely diabetes care plan was associated with better short-term blood glucose control and fewer diabetes-related admissions but not with improved blood pressure control. Delays may be a result of both patient and service-related factors.

Disparity of access to kidney transplantation by Indigenous and non-Indigenous Australians.

OBJECTIVE: To compare the likelihood of Indigenous and non-Indigenous Australians being placed on the waiting list for transplantation of a kidney from a deceased donor; to compare the subsequent likelihood of transplantation. DESIGN, SETTING AND PARTICIPANTS: Observational cohort study; analysis of data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry for patients aged 18-60 years at the start of renal replacement therapy, who commenced renal replacement therapy in Australia between 28 June 2006 and 31 December 2016. MAIN OUTCOME MEASURES: Time to wait-listing; time to kidney transplantation after wait-listing. RESULTS: 10 839 patients met the inclusion criteria, of whom 2039 (19%) were Indigenous Australians; 217 Indigenous and 3829 non-Indigenous patients were active on the waiting list at least once during the study period. The hazard ratio (HR) for wait-listing (Indigenous v non-Indigenous patients, adjusted for patient- and disease-related factors) in the first year of renal replacement therapy varied with age and remoteness (range, 0.11 [95% CI, 0.07-0.15] to 0.36 [95% CI, 0.16-0.56]); in subsequent years the adjusted HR was 0.90 (95% CI, 0.50-1.6). The adjusted HR for transplantation during the first year of wait-listing did not differ significantly from 1.0; for subsequent years of wait-listing, however, the adjusted HR was 0.40 (95% CI, 0.29-0.55). CONCLUSION: Disparities between Indigenous and non-Indigenous patients with end-stage kidney disease in access to kidney transplantation are not explained by patient- or disease-related factors. Changes in policy and practice are needed to reduce these differences.

Contribution of cardiometabolic risk factors to estimated glomerular filtration rate decline in Indigenous Australians with and without albuminuria - the eGFR Follow-up Study.

AIM: We assessed associations between cardiometabolic risk factors and estimated glomerular filtration rate (eGFR) decline according to baseline albuminuria to identify potential treatment targets in Indigenous Australians. METHODS: The eGFR Follow-up Study is a longitudinal cohort of 520 Indigenous Australians. Linear regression was used to estimate associations between baseline cardiometabolic risk factors and annual Chronic Kidney Disease Epidemiology Collaboration eGFR change (mL/min per 1.73m2 /year), among those classified with baseline normoalbuminuria (urine albumin-to-creatinine ratio (uACR) <3 mg/mmol; n = 297), microalbuminuria (uACR 3-30 mg/mmol; n = 114) and macroalbuminuria (uACR ≥30 mg/mmol; n = 109). RESULTS: After a median of 3 years follow-up, progressive declines of the age- and sex-adjusted mean eGFR were observed across albuminuria categories (-2.0 [-2.6 to -1.4], -2.5 [-3.7 to -1.3] and -6.3 [-7.8 to -4.9] mL/min per 1.72m2 /year). Although a borderline association was observed between greater baseline haemoglobin A1c and eGFR decline in those with macroalbuminuria (P = 0.059), relationships were not significant in those with microalbuminuria (P = 0.187) or normoalbuminuria (P = 0.23). Greater baseline blood pressure, C-reactive protein, waist-to-hip ratio and lower high-density lipoprotein cholesterol showed non-significant trends with greater eGFR decline in the presence of albuminuria. CONCLUSION: Over a 3 year period, marked eGFR decline was observed with greater baseline albuminuria. Cardiometabolic risk factors were not strong predictors for eGFR decline in Indigenous Australians without albuminuria. Longer follow-up may elucidate the role of these predictors and other mechanisms in chronic kidney disease progression in this population.

Estimating the total prevalence and incidence of end-stage kidney disease among Aboriginal and non-Aboriginal populations in the Northern Territory of Australia, using multiple data sources.

BACKGROUND: Most estimates for End Stage Kidney Disease (ESKD) prevalence and incidence are based on renal replacement therapy (RRT) registers. However, not all people with ESKD will commence RRT and estimates based only on RRT registry data will underestimate the true burden of ESKD in the community. This study estimates the total number of Northern Territory (NT) residents with ESKD including: those receiving RRT, those diagnosed but not receiving RRT and an estimate of "undiagnosed" cases. METHODS: Four data sources were used to identify NT residents with a diagnosis of ESKD: public hospital admissions, Australia and New Zealand Dialysis and Transplant Registry registrations, death registrations and, for the Aboriginal population only, electronic primary care records. Three data sources contained information recorded between 1 July 2008 and 31 December 2013, death registration data extended to 31 December 2014 to capture 2013 prevalent cases. A capture-recapture method was used to estimate both diagnosed and undiagnosed cases by making use of probability patterns of overlapping multiple data sources. RESULTS: In 2013, the estimated ESKD prevalence in the NT Aboriginal population was 11.01 (95% confidence interval (CI) 10.24-11.78) per 1000, and 0.90 (95% CI 0.76-1.05) per 1000 in the NT non-Aboriginal population. The age-adjusted rates were 17.97 (95% CI 17.82-18.11) and 1.07 (95% CI 1.05-1.09) per 1000 in the NT Aboriginal and non-Aboriginal populations respectively. The proportion of individuals receiving RRT was 71.4% of Aboriginal and 75.5% of non-Aboriginal prevalent ESKD cases. The age-adjusted ESKD incidence was also greater for the Aboriginal (5.26 (95% CI 4.44-6.08) per 1000 population) than non-Aboriginal population (0.36 (95% CI 0.25-0.47) per 1000). CONCLUSION: This study provides comprehensive estimates of the burden of ESKD including those cases that are not identified in relevant health data sources. The results are important for informing strategies to reduce the total burden of ESKD and to manage the potential unmet demand, particularly from comparatively young Aboriginal patients who may be suitable for RRT but do not currently access the services for social, geographic or cultural reasons.

Economic and quality of care evaluation of dialysis service models in remote Australia: protocol for a mixed methods study.

BACKGROUND: Australia's Northern Territory (NT) has the country's highest incidence and prevalence of kidney disease. Indigenous people from remote areas suffer the heaviest disease burden. Concerns regarding cost and sustainability limit the provision of dialysis treatments in remote areas and most Indigenous people requiring dialysis relocate to urban areas. However, this dislocation of people from their family, community and support networks may prove more costly when the broader health, societal and economic consequences for the individual, family and whole of government are considered. METHODS: The Dialysis Models of Care Study is a large cross organisation mixed methods study. It includes a retrospective (2000-2014) longitudinal data linkage study of two NT cohorts: Renal Cohort 1- comprising approximately 2000 adults who received dialysis and Renal Cohort 2- comprising approximately 400 children of those adults. Linkage of administrative data sets from the Australian and New Zealand Dialysis and Transplant Registry, NT Departments of Health, Housing and Education by a specialist third party (SA/NT Datalink) will enable extraction of activity, financial and outcome data. Interviews with patients, clinicians and service providers, using a snowball technique, will canvass relevant issues and assist in determining the full costs and impacts of the five most used dialysis Models of Care. DISCUSSION: The study uses a mixed methods approach to investigate the quantitative and qualitative dimensions of the full costs and outcomes associated with the choice of particular dialysis models of care for any given patient. The study includes a large data linkage component that for the first time links health, housing and education data to fully analyse and evaluate the impact on patients, their families and the broader community, resulting from the relocation of people for treatment. The study will generate a large amount of activity, financial and qualitative data that will investigate health costs less directly related to dialysis treatment, costs to government such as housing and/or education and the health, social and economic outcomes experienced by patients. This approach fills an evidence gap critical to health service planners.

Resting heart rate, physiological stress and disadvantage in Aboriginal and Torres Strait Islander Australians: analysis from a cross-sectional study.

BACKGROUND: Lower socioeconomic status has been linked to long-term stress, which can manifest in individuals as physiological stress. The aim was to explore the relationship between low socioeconomic status and physiological stress in Aboriginal and Torres Strait Islander Australians. METHODS: Using data from the eGFR Study (a cross-sectional study of 634 Indigenous Australians in urban and remote areas of northern and central Australia), we examined associations between resting heart rate and demographic, socioeconomic, and biomedical factors. An elevated resting heart rate has been proposed as a measure of sustained stress activation and was used as a marker of physiological stress. Relationships were assessed between heart rate and the above variables using univariate and multiple regression analyses. RESULTS: We reported a mean resting heart rate of 74 beats/min in the cohort (mean age 45 years). On multiple regression analysis, higher heart rate was found to be independently associated with Aboriginal ethnicity, being a current smoker, having only primary level schooling, higher HbA1c and higher diastolic blood pressure (model R(2) 0.25). CONCLUSIONS: Elevated resting heart rate was associated with lower socioeconomic status and poorer health profile in Aboriginal and Torres Strait Islander Australians. Higher resting heart rate may be an indicator of stress and disadvantage in this population at high risk of chronic diseases.

Hyperfiltration in Indigenous Australians with and without diabetes.

BACKGROUND: Hyperfiltration (HF) has been linked to the development of diabetic kidney disease (DKD), but the causative or predictive role of HF in the pathogenesis of DKD still remains unclear. To date, there have been no studies of HF in Indigenous Australians, a population with high rates of both diabetes and end-stage kidney disease. We aimed to compare the characteristics and frequency of HF in Indigenous Australians with and without type 2 diabetes. METHODS: Indigenous Australian participants, recruited across five pre-defined strata of health, diabetes status and kidney function, had a reference glomerular filtration rate (GFR) measured using plasma disappearance of iohexol [measured GFR(mGFR)] over 4 h. HF was defined in various ways: (i) mGFR > 144 mL/min/1.73 m(2), which is mGFR > 1.96 × SD above the mean of the mGFR in non-diabetic participants with normal albuminuria and normal renal function (mGFR > 90 mL/min/1.73 m(2)); (ii) age-corrected mGFR (>144 mL/min/1.73 m(2)) to account for the effect of ageing on GFR in subjects over 40 years of age with cut-off 1 mL/min/1.73 m(2) lower for every year; (iii) mGFR > 144 mL/min, without correction for body surface area or age, as well as (iv) mGFR > 125 mL/min/1.73 m(2), without adjustment for age. RESULTS: A total of 383 Indigenous participants, 125 with and 258 without diabetes, with mGFR > 90 mL/min/1.73 m(2) were studied. The proportion of participants with HF was 7% using mGFR > 144 mL/min/1.73 m(2), 11% using the age-adjusted definition, 19% using mGFR > 144 mL/min and 27% using mGFR > 125 mL/min/1.73 m(2). Diabetes was more common in participants with HF (40-74%) compared with normofiltering participants (28-31%), regardless of the definition of HF. CONCLUSIONS: HF exists in Indigenous Australians with and without diabetes. A greater proportion of participants had diabetes in HF group compared with normofiltration group. Long-term follow-up of this cohort is necessary to determine if HF plays a role in the development of DKD and non-DKD.

Survival of Indigenous Australians receiving renal replacement therapy: closing the gap?

OBJECTIVES: To compare mortality rates for Indigenous and non-Indigenous Australians commencing renal replacement therapy (RRT) over time and by categories of remoteness of place of residence. DESIGN, SETTING AND PARTICIPANTS: An observational cohort study of Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data on Indigenous and non-Indigenous Australians registered with ANZDATA who commenced RRT from 1 January 1995 to 31 December 2009 and were followed until 31 December 2011. MAIN OUTCOME MEASURES: Five-year all-cause mortality for Indigenous and non-Indigenous patients in three cohorts (1995-1999, 2000-2004 and 2005-2009) and five remoteness (of place of residence) categories. RESULTS: Indigenous patients were younger, more likely to have diabetes, be referred late and be from a more remote area than non-Indigenous patients. Age and comorbid conditions increased with successive cohorts for both groups. Unadjusted analysis (using the log-rank test) showed an increased risk of death for Indigenous patients in the 1995-1999 (P = 0.02) and 2000-2004 (P = 0.03) cohorts, but not for the 2005-2009 cohort (P = 0.7). However, a Cox proportional hazards model adjusted for covariates (age, sex, late referral and comorbid conditions [diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, lung disease], and body mass index < 18.5 kg/m(2) and > 30 kg/m(2)) showed the following Indigenous:non-Indigenous hazard ratios (with 95% CIs) for major capital cities: 1995-1999, 1.47 (1.21-1.79); 2000-2004, 1.35 (1.12-1.63); and 2005-2009, 1.37 (1.14-1.66). CONCLUSIONS: Although unadjusted analysis suggests that the survival gap between Indigenous and non-Indigenous patients receiving RRT has closed, there remains a significant disparity in survival after adjusting for the variables considered in our study.