Ultrathin ferroic HfO2-ZrO2 superlattice gate stack for advanced transistors.

With the scaling of lateral dimensions in advanced transistors, an increased gate capacitance is desirable both to retain the control of the gate electrode over the channel and to reduce the operating voltage1. This led to a fundamental change in the gate stack in 2008, the incorporation of high-dielectric-constant HfO2 (ref. 2), which remains the material of choice to date. Here we report HfO2-ZrO2 superlattice heterostructures as a gate stack, stabilized with mixed ferroelectric-antiferroelectric order, directly integrated onto Si transistors, and scaled down to approximately 20 ångströms, the same gate oxide thickness required for high-performance transistors. The overall equivalent oxide thickness in metal-oxide-semiconductor capacitors is equivalent to an effective SiO2 thickness of approximately 6.5 ångströms. Such a low effective oxide thickness and the resulting large capacitance cannot be achieved in conventional HfO2-based high-dielectric-constant gate stacks without scavenging the interfacial SiO2, which has adverse effects on the electron transport and gate leakage current3. Accordingly, our gate stacks, which do not require such scavenging, provide substantially lower leakage current and no mobility degradation. This work demonstrates that ultrathin ferroic HfO2-ZrO2 multilayers, stabilized with competing ferroelectric-antiferroelectric order in the two-nanometre-thickness regime, provide a path towards advanced gate oxide stacks in electronic devices beyond conventional HfO2-based high-dielectric-constant materials.

Postoperative Outcomes After Gastrointestinal Surgery in Patients Receiving Chronic Kidney Replacement Therapy: A Population-based Cohort Study.

OBJECTIVE: This study evaluated the postoperative mortality and morbidity outcomes following the different subtypes of gastrointestinal (GI) surgery over a 15-year period. BACKGROUND: Patients receiving chronic kidney replacement therapy (KRT) experience higher rates of general surgery compared with other surgery types. Contemporary data on the types of surgeries and their outcomes are lacking. KRT was defined as patients requiring chronic dialysis (hemodialysis or peritoneal dilaysis) or having a functioning kidney transplant long-term. METHODS: All incident and prevalent patients aged greater than 18 years identified in the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry as receiving chronic KRT were linked with jurisdictional hospital admission datasets between January 1, 2000 until December 31, 2015. Patients were categorized by their KRT modality [hemodialysis (HD), peritoneal dialysis (PD), home hemodialysis (HHD), and kidney transplant (KT)]. GI surgeries were categorized as upper gastrointestinal (UGI), bowel (small and large bowel), anorectal, hernia surgery, cholecystectomy, and appendicectomy. The primary outcome was the rates of the different surgeries, estimated using Poisson models. Secondary outcomes were risks of 30-day/in-hospital postoperative mortality risk and nonfatal outcomes and were estimated using logistic regression. Independent predictors of 30-day mortality were examined using comorbidity-adjusted Cox models. RESULTS: Overall, 46,779 patients on chronic KRT were linked to jurisdictional hospital datasets, and 9,116 patients were identified as having undergone 14,540 GI surgeries with a combined follow-up of 76,593 years. Patients on PD had the highest rates of GI surgery (8 per 100 patient years), with hernia surgery being the most frequent. Patients on PD also had the highest risk of 30-day postoperative mortality following the different types of GI surgery, with the risk being more than 2-fold higher after emergency surgery compared with elective procedures. Infective postoperative complications were more common than cardiac complications. This study also observed a U-shaped association between body mass index (BMI) and mortality, with a nadir in the 30 to 35 kg/m 2 group. CONCLUSIONS: Patients on chronic KRT have high rates of GI surgery and morbidity, particularly in those who receive PD, are older, or are either underweight or moderately obese.

Healthcare costs attributable to diabetes in pregnancy: A cost of illness study in Tasmania, Australia.

AIMS: To estimate the direct costs during the prenatal, delivery and postpartum periods in mothers with diabetes in pregnancy, compared to those without. METHODS: This study used a population-based dataset from 2004 to 2017, including 57,090 people with diabetes and 114,179 people without diabetes in Tasmania, Australia. Based on diagnostic codes, delivery episodes with gestational diabetes mellitus (GDM) were identified and matched with delivery episodes without diabetes in pregnancy. A group of delivery episodes with pre-existing diabetes was identified for comparison. Hospitalisation, emergency department and pathology costs of these groups were calculated and adjusted to 2020-2021 Australian dollars. RESULTS: There were 2774 delivery episodes with GDM, 2774 delivery episodes without diabetes and 237 delivery episodes with pre-existing diabetes identified. Across the 24-month period, the pre-existing diabetes group required the highest costs, totalling $23,536/person. This was followed by the GDM ($13,210/person), and the no diabetes group ($11,167/person). The incremental costs of GDM over the no diabetes group were $890 (95% CI 635; 1160) in the year preceding delivery; $812 (616; 1031) within the delivery period and $341 (110; 582) in the year following delivery (p < 0.05). Within the year preceding delivery, the incremental costs in the prenatal period were $803 (579; 1058) (p < 0.05). Within the year following delivery, the incremental costs in the postpartum period were $137 (55; 238) (p < 0.05). CONCLUSIONS: Our results emphasised the importance of proper management of diabetes in pregnancy in the prenatal and postpartum periods and highlighted the significance of screening and preventative strategies for diabetes in pregnancy.

Kidney Failure from Kidney Stones: An ANZDATA Registry Study.

INTRODUCTION: Kidney stones is common with an increasing trend over time and has been well studied in the general population. However, incidence and outcomes of kidney stones leading to kidney failure (KF) and receiving kidney replacement therapy (KRT) is poorly examined. We examined the incidence of KF due to kidney stones and compared outcomes to KRT patients due to other causes. METHODS: Adult patients who started KRT (January 1981-December 2020) and based in the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry. Exposure was KRT patients due to kidney stones comparing them to those with other causes. We examined incidence, prevalence, patient survival (KRT and transplant) and graft survival (transplant). Cox regression models were fit to compare patient survival between kidney stones and non-kidney stones groups, overall KRT, dialysis and patient and graft survival after kidney transplant. RESULTS: A total of 834 (1.1%) patients commenced KRT due to kidney stones. Incidence was 1.17 per million population per year and remained stable during the study period (annual percentage change -0.3% [95%CI -1.5% to 0.9%]. Survival was higher in kidney stone patients receiving dialysis compared to the non-kidney stone group (hazard ratio [HR], 0.89, 95%CI 0.82- 0.96) with similar estimates in a matched cohort. In kidney transplant patients, time to transplant was longer for patients with kidney stone compared to non-kidney stone patients (2.5 vs 1.7 years, P=0.001). There was no mortality difference (HR 1.02, 95%CI 0.82- 1.28) or graft loss (HR 1.07, 95%CI 0.79- 1.45) between kidney stones vs non-kidney stones in the kidney transplant group. CONCLUSION: KF due to kidney stones incidence is unchanged over the study period. Survival of patients with kidney stones who require KRT was better compared to patients from other causes. For the kidney transplant group, survival and risk of graft failure were similar.

Anticoagulation for people receiving long-term haemodialysis.

BACKGROUND: Haemodialysis (HD) requires safe and effective anticoagulation to prevent clot formation within the extracorporeal circuit during dialysis treatments to enable adequate dialysis and minimise adverse events, including major bleeding. Low molecular weight heparin (LMWH) may provide a more predictable dose, reliable anticoagulant effects and be simpler to administer than unfractionated heparin (UFH) for HD anticoagulation, but may accumulate in the kidneys and lead to bleeding. OBJECTIVES: To assess the efficacy and safety of anticoagulation strategies (including both heparin and non-heparin drugs) for long-term HD in people with kidney failure. Any intervention preventing clotting within the extracorporeal circuit without establishing anticoagulation within the patient, such as regional citrate, citrate enriched dialysate, heparin-coated dialysers, pre-dilution haemodiafiltration (HDF), and saline flushes were also included. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to November 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-randomised controlled studies (quasi-RCTs) evaluating anticoagulant agents administered during HD treatment in adults and children with kidney failure. DATA COLLECTION AND ANALYSIS: Two authors independently assessed the risk of bias using the Cochrane tool and extracted data. Treatment effects were estimated using random effects meta-analysis and expressed as relative risk (RR) or mean difference (MD) with 95% confidence intervals (CI). Evidence certainty was assessed using the Grading of Recommendation, Assessment, Development and Evaluation approach (GRADE). MAIN RESULTS: We included 113 studies randomising 4535 participants. The risk of bias in each study was adjudicated as high or unclear for most risk domains. Compared to UFH, LMWH had uncertain effects on extracorporeal circuit thrombosis (3 studies, 91 participants: RR 1.58, 95% CI 0.46 to 5.42; I2 = 8%; low certainty evidence), while major bleeding and minor bleeding were not adequately reported. Regional citrate anticoagulation may lower the risk of minor bleeding compared to UFH (2 studies, 82 participants: RR 0.34, 95% CI 0.14 to 0.85; I2 = 0%; low certainty evidence). No studies reported data comparing regional citrate to UFH on risks of extracorporeal circuit thrombosis and major bleeding. The effects of very LMWH, danaparoid, prostacyclin, direct thrombin inhibitors, factor XI inhibitors or heparin-grafted membranes were uncertain due to insufficient data. The effects of different LMWH, different doses of LMWH, and the administration of LMWH anticoagulants using inlet versus outlet bloodline or bolus versus infusion were uncertain. Evidence to compare citrate to another citrate or control was scant. The effects of UFH compared to no anticoagulant therapy or different doses of UFH were uncertain. Death, dialysis vascular access outcomes, blood transfusions, measures of anticoagulation effect, and costs of interventions were rarely reported. No studies evaluated the effects of treatment on non-fatal myocardial infarction, non-fatal stroke and hospital admissions. Adverse events were inconsistently and rarely reported. AUTHORS' CONCLUSIONS: Anticoagulant strategies, including UFH and LMWH, have uncertain comparative risks on extracorporeal circuit thrombosis, while major bleeding and minor bleeding were not adequately reported. Regional citrate may decrease minor bleeding, but the effects on major bleeding and extracorporeal circuit thrombosis were not reported. Evidence supporting clinical decision-making for different forms of anticoagulant strategies for HD is of low and very low certainty, as available studies have not been designed to measure treatment effects on important clinical outcomes.

Island medicine longitudinal cohort study: Rapid rise in chronic kidney disease in rural and remote communities.

AIM: To determine the change in incidence and prevalence of chronic kidney disease (CKD) in rural and remote communities over the last decade. METHODS: We examined the change in age-standardized incidence and prevalence in Tasmania between 2010 and 2020, using a linked dataset that included any adult with a creatinine test taken in a community laboratory during the study period (n = 581 513; 87.8% of the state's adult population). We defined CKD as two measures of eGFR <60 mL/min per 1.73 m2, at least 3 months apart. RESULTS: State-wide age-standardized prevalence of CKD increased by 28% in the decade to 2020, from 516 to 659 per 10 000 population. Prevalence in men increased 31.3% and women 24.8%. The greatest increase in age-standardized prevalence was seen in rural or remote communities with an increase of 36.6% overall, but with considerable variation by community (range + 0.4% to +88.3%). The increase in the actual number of people with CKD in the decade to 2020 was 67%, with the number of women increasing by 58% and men by 79%. CONCLUSION: The age-standardized prevalence of CKD in rural and remote regions has increased considerably over the past decade, likely compounded by limited access to primary and secondary healthcare. These findings highlight the need to ensure healthcare resources are directed to areas of greatest need.

The kidney failure risk equation predicts kidney failure: Validation in an Australian cohort.

AIMS: Predicting progression to kidney failure for patients with chronic kidney disease is essential for patient and clinicians' management decisions, patient prognosis, and service planning. The Tangri et al Kidney Failure Risk Equation (KFRE) was developed to predict the outcome of kidney failure. The KFRE has not been independently validated in an Australian Cohort. METHODS: Using data linkage of the Tasmanian Chronic Kidney Disease study (CKD.TASlink) and the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA), we externally validated the KFRE. We validated the 4, 6, and 8-variable KFRE at both 2 and 5 years. We assessed model fit (goodness of fit), discrimination (Harell's C statistic), and calibration (observed vs predicted survival). RESULTS: There were 18 170 in the cohort with 12 861 participants with 2 years and 8182 with 5 years outcomes. Of these 2607 people died and 285 progressed to kidney replacement therapy. The KFRE has excellent discrimination with C statistics of 0.96-0.98 at 2 years and 0.95-0.96 at 5 years. The calibration was adequate with well-performing Brier scores (0.004-0.01 at 2 years, 0.01-0.03 at 5 years) however the calibration curves, whilst adequate, indicate that predicted outcomes are systematically worse than observed. CONCLUSION: This external validation study demonstrates the KFRE performs well in an Australian population and can be used by clinicians and service planners for individualised risk prediction.

Childhood modifiable risk factors and later life chronic kidney disease: a systematic review.

BACKGROUND: Relationships between adulthood modifiable risk factors and chronic kidney disease (CKD) are well-established, but associations with childhood risk factors are unclear. This study systematically assesses the published evidence about childhood modifiable risk factors and adulthood CKD. METHODS: We searched MEDLINE, EMBASE, and Web of Science to 6th May 2022. Articles were included if (1) they were population-based longitudinal studies, (2) exposures were potentially modifiable, for example through pharmacological or lifestyle modifications, including clinical conditions/measures (diabetes, blood pressure, adiposity, and dyslipidaemia); health behaviours (smoking, alcohol consumption, physical activity, fitness, and poor nutrition); and socio-economic factors (socio-economic position), and occurred during childhood (ages 2-19 years), and (3) outcome was CKD or surrogate markers of CKD in adulthood (ages 20 years or older). Three reviewers independently extracted the data. RESULTS: 15,232 articles were identified after deduplication; 17 articles met the inclusion criteria, reporting childhood blood pressure (n = 8), adiposity (n = 4), type 2 diabetes (n = 1), socio-economic position (n = 1), famine (n = 1), cardiorespiratory fitness (n = 1), and a healthy lifestyle score (n = 1). The results suggested positive associations of childhood adiposity, type 2 diabetes, and low socio-economic position and cardiorespiratory fitness in females with CKD in adulthood. Findings were inconsistent on associations between childhood BP and CKD in adulthood. Childhood healthy lifestyle score and exposure to famine were not associated with risk of CKD in adulthood. CONCLUSIONS: The limited evidence suggests childhood factors may contribute to the CKD risk in adulthood, particularly adiposity, type 2 diabetes, and low socio-economic position and cardiorespiratory fitness in females. Further high-quality community-based studies are needed with long-term follow-up and investigation of a broader range of modifiable risk factors.

Trends in Rates of Surgery and Postoperative Mortality Among Patients Receiving Chronic Kidney Replacement Therapy: A Population-based Cohort Study.

OBJECTIVE: To estimate the incidence and postoperative mortality rates of surgery, and variations by age, diabetes, kidney replacement therapy (KRT) modality, and time over a 15-year period. BACKGROUND: Patients with kidney failure receiving chronic KRT (dialysis or kidney transplantation) have increased risks of postoperative mortality and morbidity. Contemporary data on the incidence and types of surgery these patients undergo are lacking. METHODS: This binational population cohort study evaluated all incident and prevalent patients receiving chronic KRT using linked data between Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry and jurisdictional hospital admission datasets between 2000 and 2015. Patients were categorized by their KRT modality (hemodialysis, peritoneal dialysis, home hemodialysis, and kidney transplant) for each calendar year. Incidence rates for overall surgery and subtypes were estimated using Poisson models. Logistic regression was used to estimate 30-day/in-hospital mortality risk. RESULTS: Overall, 46,497 patients over a median (interquartile range) follow-up of 6.3 years (3.5-10.2 years) underwent 81,332 surgeries. The median incidence rate of surgery remained stable over this period with a median of 14.9 surgeries per 100 patient-years. Annual incidence rate was higher in older people and those with diabetes mellitus. Patients receiving hemodialysis had a higher incidence rate of surgery compared with kidney transplant recipients (15.8 vs 10.0 surgeries per 100 patient-years, respectively). Overall adjusted postoperative mortality rates decreased by >70% over the study period, and were lowest in kidney transplant recipients (1.7%, 95% confidence interval, 1.4-2.0). Postoperative mortality following emergency surgery was >3-fold higher than elective surgery (8.4% vs 2.3%, respectively). CONCLUSIONS: Patients receiving chronic KRT have high rates of surgery and morbidity. Further research into strategies to mitigate perioperative risk remain a priority.

Incremental healthcare expenditure attributable to diabetes mellitus: A cost of illness study in Tasmania, Australia.

AIMS: To quantify the incremental direct medical costs in people with diabetes from the healthcare system perspective; and to identify trends in the incremental costs. METHODS: This was a matched retrospective cohort study based on a linked data set developed for investigating chronic kidney disease in Tasmania, Australia. Using propensity score matching, 51,324 people with diabetes were matched on age, sex and residential area with 102,648 people without diabetes. Direct medical costs (Australian dollars 2020-2021) due to hospitalisation, Emergency Department visits and pathology tests were included. The incremental costs and cost ratios between mean annual costs of people with diabetes and their controls were calculated. RESULTS: On average, people with diabetes had healthcare costs that were almost double their controls ($2427 [95% CI 2322-2543]; ratio 1.87 [95% CI 1.85-1.91]; pooled from 2007-2017). While in the first year of follow-up, the costs of a person with diabetes were $1643 (95% CI 1489-1806); ratio 1.83 (95% CI 1.76-1.92) more than their control, this increased to $2480 (95% CI 2265-2680); ratio 1.69 (95% CI 1.62-1.77) in the final year. Although the incremental costs were higher in older age groups (e.g., ≥70: $2498 [95% CI 2265-2754]; 40-49: $2117 [95% CI 1887-2384]), the cost ratios were higher in younger age groups (≥70: 1.52 [95% CI 1.48-1.56]; 40-49: 2.37 [95% CI 2.25-2.61]). CONCLUSIONS: Given the increasing burden that diabetes imposes, our findings will support policymakers in future planning for diabetes and enable targeting sub-groups with higher long-term costs for possible cost savings for the Tasmanian healthcare system.

Temporal changes and risk factors for death from early withdrawal within 12 months of dialysis initiation-a cohort study.

BACKGROUND: Mortality risk is high soon after dialysis initiation in patients with kidney failure, and dialysis withdrawal is a major cause of early mortality, attributed to psychosocial or medical reasons. The temporal trends and risk factors associated with cause-specific early dialysis withdrawal within 12 months of dialysis initiation remain uncertain. METHODS: Using data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the temporal trends and risk factors associated with mortality attributed to early psychosocial and medical withdrawals in incident adult dialysis patients in Australia between 2005 and 2018 using adjusted competing risk analyses. RESULTS: Of 32 274 incident dialysis patients, 3390 (11%) experienced death within 12 months post-dialysis initiation. Of these, 1225 (36%) were attributed to dialysis withdrawal, with 484 (14%) psychosocial withdrawals and 741 (22%) medical withdrawals. These patterns remained unchanged over the past two decades. Factors associated with increased risk of death from early psychosocial and medical withdrawals were older age, dialysis via central venous catheter, late referral and the presence of cerebrovascular disease; obesity and Asian ethnicity were associated with decreased risk. Risk factors associated with early psychosocial withdrawals were underweight and higher socioeconomic status. Presence of peripheral vascular disease, chronic lung disease and cancers were associated with early medical withdrawals. CONCLUSIONS: Death from dialysis withdrawal accounted for >30% of early deaths in kidney failure patients initiated on dialysis and remained unchanged over the past two decades. Several shared risk factors were observed between mortality attributed to early psychosocial and medical withdrawals.

Competing risks of death and kidney failure in a cohort of Australian adults with severe chronic kidney disease.

OBJECTIVES: To examine the competing risks of death (any cause) and of kidney failure in a cohort of Australian adults with severe chronic kidney disease. DESIGN: Population-based cohort study; analysis of linked data from the Tasmanian Chronic Kidney Disease study (CKD.TASlink), 1 January 2004 - 31 December 2017. PARTICIPANTS: All adults in Tasmania with incident stage 4 chronic kidney disease (estimated glomerular filtration rate [eGFR], 15-29 mL/min/1.73 m2 ). MAIN OUTCOME MEASURES: Death or kidney failure (defined as eGFR below 10 mL/min/1.73 m2 or initiation of dialysis or kidney transplantation) within five years of diagnosis of stage 4 chronic kidney disease. RESULTS: We included data for 6825 adults with incident stage 4 chronic kidney disease (mean age, 79.3 years; SD, 11.1 years), including 3816 women (55.9%). The risk of death increased with age - under 65 years: 0.18 (95% CI, 0.15-0.22); 65-74 years: 0.39 (95% CI, 0.36-0.42); 75-84 years, 0.56 (95% CI, 0.54-0.58); 85 years or older: 0.78 (95% CI, 0.77-0.80) - while that of kidney failure declined - under 65 years: 0.39 (95% CI, 0.35-0.43); 65-74 years: 0.12 (95% CI, 0.10-0.14); 75-84 years: 0.05 (95% CI, 0.04-0.06); 85 years or older: 0.01 (95% CI, 0.01-0.02). The risk of kidney failure was greater for people with macroalbuminuria and those whose albumin status had not recently been assessed. The risks of kidney failure and death were greater for men than women in all age groups (except similar risks of death for men and women under 65 years of age). CONCLUSIONS: For older Australians with incident stage 4 chronic kidney disease, the risk of death is higher than that of kidney failure, and the latter risk declines with age. Clinical guidelines should recognise these competing risks and include recommendations about holistic supportive care, not just on preparation for dialysis or transplantation.

Associations of a healthy lifestyle score from childhood to adulthood with subclinical kidney damage in midlife: a population-based cohort study.

BACKGROUND: The relationships of healthy lifestyle scores (HLS) of various kinds in adulthood with the risk of chronic kidney disease (CKD) have been reported, but little is known about the association of childhood lifestyle with later life CKD. This study examined the relationship of HLS from childhood to adulthood with subclinical kidney damage (SKD) in midlife, a surrogate measure for CKD. METHODS: Data were collected in an Australian population-based cohort study with 33 years follow-up. 750 participants with lifestyle information collected in childhood (ages 10-15 years) and midlife (ages 40-50 years), and measures of kidney function in midlife were included. The HLS was generated from the sum scores of five lifestyle factors (body mass index, smoking, alcohol consumption, physical activity, and diet). Each factor was scored as poor (0 point), intermediate (1 point), or ideal (2 points). Log-binomial regression was used to investigate the relationship of HLS in childhood and from childhood to adulthood with SKD defined as either 1) estimated glomerular filtration rate (eGFR) 30-60 mL/min/1.73m2 or 2) eGFR> 60 mL/min/1.73m2 with urine albumin-creatinine ratio ≥ 2.5 mg/mmol (males) or 3.5 mg/mmol (females), adjusting for socio-demographic factors and the duration of follow-up. RESULTS: The average HLS was 6.6 in childhood and 6.5 in midlife, and the prevalence of SKD was 4.9% (n = 36). Neither HLS in childhood nor HLS from childhood to adulthood were significantly associated with the risk of SKD in midlife. CONCLUSIONS: A HLS from childhood to adulthood did not predict SKD in this middle-aged, population-based Australian cohort.

Identifying new-onset conditions and pre-existing conditions using lookback periods in Australian health administrative datasets.

BACKGROUND: The condition onset flag (COF) variable was introduced into the hospitalization coding practice in 2008 to help distinguish between the new and pre-existing conditions. However, Australian datasets collected prior to 2008 lack the COF, potentially leading to data waste. The aim of this study was to determine if an algorithm to lookback across the previous admissions could make this distinction. METHODS: All patients requiring kidney replacement therapy (KRT) identified in the Australia and New Zealand Dialysis and Transplant Registry in New South Wales, South Australia and Tasmania between July 2008 and December 2015 were linked with hospital admission datasets using probabilistic linkage. Three different lookback periods entailing either one, two or three admissions prior to the index admission were investigated. Conditions identified in an index admission but not in the lookback periods were classified as a new-onset condition. Conditions identified in both the index admission and the lookback period were deemed to be pre-existing. The degrees of agreement were determined using the kappa statistic. Conditions examined for new onset were myocardial infarction, pulmonary embolism and pneumonia. Conditions examined for prior existence were diabetes mellitus, hypertension and kidney failure. Secondary analyses evaluated whether the conditions identified as pre-existing using COF were captured consistently in the subsequent admissions. RESULTS: 11 140 patients on KRT with 69 403 admissions were analysed. Lookback over a single admission interval (Period 1) provided the highest rates of true positives with COF for all three new-onset conditions, ranging from 89% to 100%. The levels of agreement were almost perfect for all conditions (k = 0.94-1.00). This was consistent across the different time eras. All lookback periods identified additional new-onset conditions that were not classified by COF: Lookback Period 1 picked up a further 474 myocardial infarction, 84 pulmonary embolism and 1092 pneumonia episodes. Lookback Period 1 had the highest percentage of true positives when identifying the pre-existing conditions (64-80%). The level of agreement was moderate to strong and was similar across the time eras. Secondary analysis showed that not all pre-existing conditions identified using COF carried forward to the subsequent admission (61-82%) but increased when looking forward across >1 admission (87-95%). CONCLUSION: The described algorithm using a lookback period is a pragmatic, reliable and robust means of identifying the new-onset and pre-existing patient conditions, thereby enriching the existing datasets predating the availability of the COF. The findings also highlight the value of concatenating a series of hospital patient admissions to more comprehensively adjudicate the pre-existing conditions, rather than assessing the index admission alone.

Acute kidney injury, stroke and death after cardiopulmonary bypass surgery: the role of perfusion flow and pressure.

INTRODUCTION: Acute kidney injury after cardiopulmonary bypass surgery is associated with morbidity and mortality. This study aims to evaluate the role of low perfusion flow and pressure in the development of cardiopulmonary bypass-associated acute kidney injury, stroke and death, using multicentre registry data. METHODS: We identified patients from the Australian and New Zealand Collaborative Perfusion Registry who underwent coronary artery bypass grafting and/or valvular surgery between 2008 and 2018. Primary predictor variables were the length of time the perfusion flow was <1.6 L/min/m2 and the length of time perfusion pressure was < 50mmHg. The primary outcome was new postoperative acute kidney injury defined by the risk-injury-failure-loss-end stage criteria. Secondary outcomes were stroke and in-hospital death. The influence of perfusion flow and pressure during cardiopulmonary bypass on the primary and secondary outcomes was estimated using separate multivariate models. RESULTS: A total of 16,356 patients were included. The mean age was 66 years and 75% were male. Acute kidney injury was observed in 1,844 patients (11%), stroke in 204 (1.3%) and in-hospital death in 286 (1.8%). Neither the duration of the time spent for perfusion flow (<1.6 L/minute/m2) nor the duration of the time spent for perfusion pressure (<50 mmHg) was associated with postoperative acute kidney injury, stroke or death in adjusted models. CONCLUSIONS: Neither low perfusion pressure nor low perfusion flow during cardiopulmonary bypass were predictive of postoperative acute kidney injury, stroke or death.

Evaluation of a young adult renal and transplant transition clinic in a regional setting: Supporting young adults and parents' transition to self-management.

OBJECTIVE: This study evaluated the impact of establishing a transition clinic in a regional Australian setting on the lives of young adults living with severe chronic kidney disease and their families. DESIGN: A qualitative design using the experience-based co-design framework. SETTING: Interviews were held at the Royal Hobart Hospital or the Menzies Institute for Medical Research. The co-design workshop was held at the Royal Hobart Hospital. PARTICIPANTS: Young people aged 17-29 years living with a kidney transplant or stage 4-5 chronic kidney disease, parents/carers and health professionals. INTERVENTIONS: Establishment of a young adult renal and transplant clinic. MAIN OUTCOME MEASURE: Impact of a transition clinic in a regional setting on the lives of young adults living with chronic kidney disease and their families and suggestions for improvement. RESULTS: Four key themes were identified as follows: The Model of Care; Peer support; Transition towards self-management: Building life skills; Suggestions for improvement and limitations of the service model. The non-institutional, informal clinic setting and social/educational activities facilitated engagement, self-management and peer support for young people and parents. Suggestions for improvement included involvement of older peers, additional life skills sessions and a youth worker. CONCLUSION: This regional transition clinic is valued by the young people and their parents for generating peer support, building self-management and life skills. Sustainability of the clinic depends upon having the appropriate expertise available, access to a suitable venue and offering a program that meets the needs of young people.

Independent effect of haemodialysis session frequency and duration on survival in non-indigenous Australians on haemodialysis.

BACKGROUND: End-stage kidney disease patients have increased mortality compared to the general population. Haemodialysis (HD) of more frequent and of longer duration has been proposed to improve survival but it remains unclear if this is attributed to increased frequency, duration, or both. We aimed to examine the independent effects of session frequency and duration on mortality in incident HD patients. METHODS: A retrospective cohort study was performed using data from the Australian and New Zealand Dialysis and Transplant Registry examining non-Indigenous patients aged ≥18 years who initiated HD of ≥3 sessions/week in Australia from 2001 to 2015. Initial dialysis prescription was categorized as session duration >5 h/session compared to ≤5 h/session and session frequency as >3 sessions/week compared to 3 sessions/week. Survival analysis was performed using Cox regression analysis, with multivariable analysis controlling for available covariates. RESULTS: We examined 16 944 patients of whom 757 (4.5%) received >3 sessions/week and 518 (3.1%) received >5 h/session. After controlling for frequency, patients initiated on HD sessions >5 h had a significantly reduced risk of mortality compared with patients with HD session ≤5 h (adjusted hazard ratio (HR) = 0.57; 95% confidence interval (CI) = 0.44-0.74). In contrast, patients initiated on >3 sessions/week of HD had a similar risk of death when compared with patients on 3 sessions/week of HD (adjusted HR = 0.97; 95% CI = 0.84-1.13), after controlling for duration. Limitations include potential residual confounding and changes in exposure over time. CONCLUSION: Longer duration rather than increased frequency of treatment appears to reduce mortality in HD patients. This has implications for management and requires further study.

Use of patient-reported outcome measures and patient-reported experience measures in renal units in Australia and New Zealand: A cross-sectional survey study.

AIM: Patient-reported outcome measures (PROMs) and patient-reported experience measures (PREMs) are increasingly used in research to quantify how patients feel and function, and their experiences of care, however, knowledge of their utilization in routine nephrology is limited. METHODS: The Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) PROMs working group conducted a prospective cross-sectional survey of PROMs/PREMs use among renal 'parent hospitals'. One survey per hospital was completed (August-November 2017). Descriptive statistics reported type and frequency of measures used and purpose of use. RESULTS: Survey response rate was 100%. Fifty-five of 79 hospitals (70%) used at least one PROMs or PREMs for specific patient groups. PROMs were more likely to be collected from patients receiving comprehensive conservative care (45% of hospitals) than dialysis patients (32%, 31% and 28% of hospitals for home haemodialysis, peritoneal dialysis and facility dialysis, respectively). Few renal transplanting hospitals (3%) collected PROMs. The Integrated Palliative Outcome Scale-Renal (IPOS-Renal) (40% of units), and the Euro-Qol (EQ-5D-5 L) (25%), were most frequently used. The main reason for collecting PROMs was to inform clinical care (58%), and for PREMs was to fulfil private dialysis/hospital provider requirements (25%). The most commonly reported reason for not using PROMs in 24 hospitals was insufficient staff resources (79%). Sixty-two hospitals (78%) expressed interest in participating in a registry-based PROMs trial. CONCLUSION: Many renal hospitals in Australia and New Zealand collect PROMs and/or PREMs as part of clinical care with use varying by treatment modality. Resources are a key barrier to PROMs use.

Enabling good outcomes in older adults on dialysis: a qualitative study.

BACKGROUND: Older patients on dialysis may not have optimal outcomes, particularly with regards to quality of life. Existing research is focused mainly on survival, with limited information about other outcomes. Such information can help in shared decision-making around dialysis initiation; it can also be used to improve outcomes in patients established on dialysis. We used qualitative research methods to explore patient perspectives regarding their experience and outcomes with dialysis. METHODS: Semi-structured interviews with participants aged ≥70, receiving dialysis at a regional Australian hospital, were recorded and transcribed. From participants' responses, we identified descriptive themes using a phenomenological approach, with verification by two researchers. Factors affecting outcomes were derived reflexively from these themes. RESULTS: Seventeen interviews were analysed prior to saturation of themes. Participants (12 on haemodialysis, 5 on peritoneal dialysis) had spent an average of 4.3 years on dialysis. There were 11 males and 6 females, with mean age 76.2 years (range 70 to 83). Experiences of dialysis were described across four domains - the self, the body, effects on daily life and the influences of others; yielding themes of (i) responses to loss (of time, autonomy, previous life), (ii) responses to uncertainty (variable symptoms; unpredictable future; dependence on others), (iii) acceptance / adaptation (to life on dialysis; to ageing) and (iv) the role of relationships / support (family, friends and clinicians). CONCLUSIONS: Older patients experience the effects of dialysis across multiple domains in their lives. They endure feelings of loss and persistent uncertainty, but may also adapt successfully to their new circumstances, aided by the support they receive from family, health professionals and institutions. From these insights, we have suggested practical measures to improve outcomes in older patients.

Quality use of medicines in patients with chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) affects drug elimination and patients with CKD require appropriate adjustment of renally cleared medications to ensure safe and effective pharmacotherapy. The main objective of this study was to determine the extent of potentially inappropriate prescribing (PIP; defined as the use of a contraindicated medication or inappropriately high dose according to the kidney function) of renally-cleared medications commonly prescribed in Australian primary care, based on two measures of kidney function. A secondary aim was to assess agreement between the two measures. METHODS: Retrospective analysis of routinely collected de-identified Australian general practice patient data (NPS MedicineWise MedicineInsight from January 1, 2013, to June 1, 2016; collected from 329 general practices). All adults (aged ≥18 years) with CKD presenting to general practices across Australia were included in the analysis. Patients were considered to have CKD if they had two or more estimated glomerular filtration rate (eGFR) recorded values < 60 mL/min/1.73m2, and/or two urinary albumin/creatinine ratios ≥3.5 mg/mmol in females (≥2.5 mg/mmol in males) at least 90 days apart. PIP was assessed for 49 commonly prescribed medications using the Cockcroft-Gault (CG) equation/eGFR as per the instructions in the Australian Medicines Handbook. RESULTS: A total of 48,731 patients met the Kidney Health Australia (KHA) definition for CKD and had prescriptions recorded within 90 days of measuring serum creatinine (SCr)/estimated glomerular filtration rate (eGFR). Overall, 28,729 patients were prescribed one or more of the 49 medications of interest. Approximately 35% (n = 9926) of these patients had at least one PIP based on either the Cockcroft-Gault (CG) equation or eGFR (CKD-EPI; CKD-Epidemiology Collaboration Equation). There was good agreement between CG and eGFR while determining the appropriateness of medications, with approximately 97% of the medications classified as appropriate by eGFR also being considered appropriate by the CG equation. CONCLUSION: This study highlights that PIP commonly occurs in primary care patients with CKD and the need for further research to understand why and how this can be minimised. The findings also show that the eGFR provides clinicians a potential alternative to the CG formula when estimating kidney function to guide drug appropriateness and dosing.