Calciphylaxis Episodes in the Australia and New Zealand Dialysis and Transplant Registry.

Introduction: Calciphylaxis is a rare disorder associated with significant morbidity and mortality. Data registries are an invaluable source of information for rare diseases. We reviewed cases of calciphylaxis recorded in the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) and evaluated associations and outcomes of this condition. Methods: Data was obtained on all cases of calciphylaxis reported between 2019 and 2022 in Australian and New Zealand patients on kidney replacement therapy (KRT). This cohort was compared to all patients in the registry who received KRT from 2019 to 2022 without an episode of calciphylaxis. Cox proportional hazards regression including a time-varying covariate for calciphylaxis episode was conducted for mortality with models restricted to patients on dialysis only. Results: From 2019 to 2022, 333 patients had calciphylaxis episodes reported. Overall incidence rate for patients on dialysis was 4.5 (4.1-5.1) episodes per 1000 patient-years on dialysis. Median age was 63 (interquartile range [IQR]: 55-73) years, 54% were female, 66% had diabetes, 59% were obese (body mass index [BMI] ≥ 30 kg/m2) and 77% were receiving hemodialysis (HD) treatment. Compared to patients without calciphylaxis (n = 46,526), patients with calciphylaxis were more likely to be older, female, and have diabetes, greater BMI, coronary artery, and peripheral vascular disease. The median time to calciphylaxis was 3.2 (IQR: 0.9-6.7) years after KRT commencement. Half of the patients with calciphylaxis died by 12 months from diagnosis. Adjusted hazard ratio (HR) of mortality for patients on dialysis with calciphylaxis <1 year and 1 to 4 years after an episode was 5.8 (4.9-6.9) and 1.5 (1.0-2.1), respectively compared to patients on dialysis without calciphylaxis. Conclusion: Calciphylaxis is a rare but life-threatening condition in people on KRT with the greatest mortality burden within 12 months of diagnosis.

Association between diabetic status and risk of all-cause and cause-specific mortality on dialysis following first kidney allograft loss.

Background: Diabetes mellitus (DM) is associated with a greater risk of mortality in kidney transplant patients, primarily driven by a greater risk of cardiovascular disease (CVD)-related mortality. However, the associations between diabetes status at time of first allograft loss and mortality on dialysis remain unknown. Methods: All patients with failed first kidney allografts transplanted in Australia and New Zealand between 2000 and 2020 were included. The associations between diabetes status at first allograft loss, all-cause and cause-specific mortality were examined using competing risk analyses, separating patients with diabetes into those with pre-transplant DM or post-transplant diabetes mellitus (PTDM). Results: Of 3782 patients with a median (IQR) follow-up duration of 2.7 (1.1-5.4) years, 539 (14%) and 390 (10%) patients had pre-transplant DM or developed PTDM, respectively. In the follow-up period, 1336 (35%) patients died, with 424 (32%), 264 (20%) and 199 (15%) deaths attributed to CVD, dialysis withdrawal and infection, respectively. Compared to patients without DM, the adjusted subdistribution HRs (95% CI) for pre-transplant DM and PTDM for all-cause mortality on dialysis were 1.47 (1.17-1.84) and 1.47 (1.23-1.76), respectively; for CVD-related mortality were 0.81 (0.51-1.29) and 1.02 (0.70-1.47), respectively; for infection-related mortality were 1.84 (1.02-3.35) and 2.70 (1.73-4.20), respectively; and for dialysis withdrawal-related mortality were 1.71 (1.05-2.77) and 1.51 (1.02-2.22), respectively. Conclusions: Patients with diabetes at the time of kidney allograft loss have a significant survival disadvantage, with the excess mortality risk attributed to infection and dialysis withdrawal.

PD peritonitis in patients undergoing capsule endoscopy: A descriptive study.

Peritoneal dialysis (PD) patients who undergo gastroendoscopy and colonoscopy are at increased risk of peritoneal dialysis-associated peritonitis (PD peritonitis) following the procedure (defined as occurring within 7 days of intervention). As per current International Society for PD (ISPD) guidelines, antibiotic prophylaxis is currently recommended pre-colonoscopy in PD patients given the risk of post-colonoscopy PD peritonitis. The risk of PD peritonitis in patients undergoing capsule endoscopy (CE) is unknown. This binational data-linkage study between the Australia and New Zealand Dialysis and Transplant Registry and all hospital admission data sets in Australia and New Zealand evaluated all patients with PD who underwent CE between 2006 and 2015. The objective of the study was to assess the risk of PD peritonitis in patients undergoing CE. Descriptive statistics were used to describe patient characteristics and clinical outcomes. Overall, 23 patients with PD underwent CE. Twelve patients underwent CE alone (i.e. no other concomitant procedures) and none of these patients experienced an episode of PD peritonitis. The remaining 11 patients underwent CE and other invasive endoscopic/abdominal surgical procedures, of whom 2 suffered PD peritonitis. CE is likely a relatively safe procedure in PD patients. PD patients undergoing CE may not require prior antibiotic prophylaxis. Given their relative safety, CE may be an appealing diagnostic tool in a select group of PD patients for the investigation of gastrointestinal disease.

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.

Monogenic and polygenic concepts in chronic kidney disease (CKD).

Kidney function is strongly influenced by genetic factors with both monogenic and polygenic factors contributing to kidney function. Monogenic disorders with primarily autosomal dominant inheritance patterns account for 10% of adult and 50% of paediatric kidney diseases. However, kidney function is also a complex trait with polygenic architecture, where genetic factors interact with environment and lifestyle factors. Family studies suggest that kidney function has significant heritability at 35-69%, capturing complexities of the genome with shared environmental factors. Genome-wide association studies estimate the single nucleotide polymorphism-based heritability of kidney function between 7.1 and 20.3%. These heritability estimates, measuring the extent to which genetic variation contributes to CKD risk, indicate a strong genetic contribution. Polygenic Risk Scores have recently been developed for chronic kidney disease and kidney function, and validated in large populations. Polygenic Risk Scores show correlation with kidney function but lack the specificity to predict individual-level changes in kidney function. Certain kidney diseases, such as membranous nephropathy and IgA nephropathy that have significant genetic components, may benefit most from polygenic risk scores for improved risk stratification. Genetic studies of kidney function also provide a potential avenue for the development of more targeted therapies and interventions. Understanding the development and validation of genomic scores is required to guide their implementation and identify the most appropriate potential implications in clinical practice. In this review, we provide an overview of the heritability of kidney function traits in population studies, explore both monogenic and polygenic concepts in kidney disease, with a focus on recently developed polygenic risk scores in kidney function and chronic kidney disease, and review specific diseases which are most amenable to incorporation of genomic scores.

Embedding stakeholder preferences in setting priorities for health research: Using a discrete choice experiment to develop a multi-criteria tool for evaluating research proposals.

We determined weights for a multi-criteria tool for assessing the relative merits of clinical-trial research proposals, and investigated whether the weights vary across relevant stakeholder groups. A cross-sectional, adaptive discrete choice experiment using 1000minds online software was administered to consumers, researchers and funders affiliated with the Australian Clinical Trials Alliance (ACTA). We identified weights for four criteria-Appropriateness, Significance, Relevance, Feasibility-and their levels, representing their relative importance, so that research proposals can be scored between 0% (nil or very low merit) and 100% (very high merit). From 220 complete survey responses, the most important criterion was Appropriateness (adjusted for differences between stakeholder groups, mean weight 28.9%) and the least important was Feasibility (adjusted mean weight 19.5%). Consumers tended to weight Relevance more highly (2.7% points difference) and Feasibility less highly (3.1% points difference) than researchers. The research or grant writing experience of researchers or consumers was not associated with the weights. A multi-criteria tool for evaluating research proposals that reflects stakeholders' preferences was created. The tool can be used to assess the relative merits of clinical trial research proposals and rank them, to help identify the best proposals for funding.

Multi-center, pragmatic, cluster-randomized, controlled trial of standardized peritoneal dialysis (PD) training versus usual care on PD-related infections (the TEACH-PD trial): trial protocol.

BACKGROUND: Peritoneal dialysis (PD)-related infections, such as peritonitis, exit site, and tunnel infections, substantially impair the sustainability of PD. Accordingly, PD-related infection is the top-priority research outcome for patients and caregivers. While PD nurse trainers teach patients to perform their own PD, PD training curricula are not standardized or informed by an evidentiary base and may offer a potential approach to prevent PD infections. The Targeted Education ApproaCH to improve Peritoneal Dialysis outcomes (TEACH-PD) trial evaluates whether a standardized training curriculum for PD nurse trainers and incident PD patients based on the International Society for Peritoneal Dialysis (ISPD) guidelines reduces PD-related infections compared to usual training practices. METHODS: The TEACH-PD trial is a registry-based, pragmatic, open-label, multi-center, binational, cluster-randomized controlled trial. TEACH-PD will recruit adults aged 18 years or older who have not previously undergone PD training at 42 PD treatment units (clusters) in Australia and New Zealand (ANZ) between July 2019 and June 2023. Clusters will be randomized 1:1 to standardized TEACH-PD training curriculum or usual training practice. The primary trial outcome is the time to the first occurrence of any PD-related infection (exit site infection, tunnel infection, or peritonitis). The secondary trial outcomes are the individual components of the primary outcome, infection-associated catheter removal, transfer to hemodialysis (greater than 30 days and 180 days), quality of life, hospitalization, all-cause death, a composite of transfer to hemodialysis or all-cause death, and cost-effectiveness. Participants are followed for a minimum of 12 months with a targeted average follow-up period of 2 years. Participant and outcome data are collected from the ANZ Dialysis and Transplant Registry (ANZDATA) and the New Zealand Peritoneal Dialysis (NZPD) Registry. This protocol follows the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines. DISCUSSION: TEACH-PD is a registry-based, cluster-randomized pragmatic trial that aims to provide high-certainty evidence about whether an ISPD guideline-informed standardized PD training curriculum for PD nurse trainers and adult patients prevents PD-related infections. TRIAL REGISTRATION: ClinicalTrials.gov NCT03816111. Registered on 24 January 2019.

Synbiotics, prebiotics and probiotics for people with chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a major public health problem affecting 13% of the global population. Prior research has indicated that CKD is associated with gut dysbiosis. Gut dysbiosis may lead to the development and/or progression of CKD, which in turn may in turn lead to gut dysbiosis as a result of uraemic toxins, intestinal wall oedema, metabolic acidosis, prolonged intestinal transit times, polypharmacy (frequent antibiotic exposures) and dietary restrictions used to treat CKD. Interventions such as synbiotics, prebiotics, and probiotics may improve the balance of the gut flora by altering intestinal pH, improving gut microbiota balance and enhancing gut barrier function (i.e. reducing gut permeability). OBJECTIVES: This review aimed to evaluate the benefits and harms of synbiotics, prebiotics, and probiotics for people with CKD. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 9 October 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: We included randomised controlled trials (RCTs) measuring and reporting the effects of synbiotics, prebiotics, or probiotics in any combination and any formulation given to people with CKD (CKD stages 1 to 5, including dialysis and kidney transplant). Two authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria. DATA COLLECTION AND ANALYSIS: Data extraction was independently carried out by two authors using a standard data extraction form. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: Forty-five studies (2266 randomised participants) were included in this review. Study participants were adults (two studies in children) with CKD ranging from stages 1 to 5, with patients receiving and not receiving dialysis, of whom half also had diabetes and hypertension. No studies investigated the same synbiotic, prebiotic or probiotic of similar strains, doses, or frequencies. Most studies were judged to be low risk for selection bias, performance bias and reporting bias, unclear risk for detection bias and for control of confounding factors, and high risk for attrition and other biases. Compared to prebiotics, it is uncertain whether synbiotics improve estimated glomerular filtration rate (eGFR) at four weeks (1 study, 34 participants: MD -3.80 mL/min/1.73 m², 95% CI -17.98 to 10.38), indoxyl sulfate at four weeks (1 study, 42 participants: MD 128.30 ng/mL, 95% CI -242.77 to 499.37), change in gastrointestinal (GI) upset (borborymgi) at four weeks (1 study, 34 participants: RR 15.26, 95% CI 0.99 to 236.23), or change in GI upset (Gastrointestinal Symptom Rating Scale) at 12 months (1 study, 56 participants: MD 0.00, 95% CI -0.27 to 0.27), because the certainty of the evidence was very low. Compared to certain strains of prebiotics, it is uncertain whether a different strain of prebiotics improves eGFR at 12 weeks (1 study, 50 participants: MD 0.00 mL/min, 95% CI -1.73 to 1.73), indoxyl sulfate at six weeks (2 studies, 64 participants: MD -0.20 µg/mL, 95% CI -1.01 to 0.61; I² = 0%) or change in any GI upset, intolerance or microbiota composition, because the certainty of the evidence was very low. Compared to certain strains of probiotics, it is uncertain whether a different strain of probiotic improves eGFR at eight weeks (1 study, 30 participants: MD -0.64 mL/min, 95% CI -9.51 to 8.23; very low certainty evidence). Compared to placebo or no treatment, it is uncertain whether synbiotics improve eGFR at six or 12 weeks (2 studies, 98 participants: MD 1.42 mL/min, 95% CI 0.65 to 2.2) or change in any GI upset or intolerance at 12 weeks because the certainty of the evidence was very low. Compared to placebo or no treatment, it is uncertain whether prebiotics improves indoxyl sulfate at eight weeks (2 studies, 75 participants: SMD -0.14 mg/L, 95% CI -0.60 to 0.31; very low certainty evidence) or microbiota composition because the certainty of the evidence is very low. Compared to placebo or no treatment, it is uncertain whether probiotics improve eGFR at eight, 12 or 15 weeks (3 studies, 128 participants: MD 2.73 mL/min, 95% CI -2.28 to 7.75; I² = 78%), proteinuria at 12 or 24 weeks (1 study, 60 participants: MD -15.60 mg/dL, 95% CI -34.30 to 3.10), indoxyl sulfate at 12 or 24 weeks (2 studies, 83 participants: MD -4.42 mg/dL, 95% CI -9.83 to 1.35; I² = 0%), or any change in GI upset or intolerance because the certainty of the evidence was very low. Probiotics may have little or no effect on albuminuria at 12 or 24 weeks compared to placebo or no treatment (4 studies, 193 participants: MD 0.02 g/dL, 95% CI -0.08 to 0.13; I² = 0%; low certainty evidence). For all comparisons, adverse events were poorly reported and were minimal (flatulence, nausea, diarrhoea, abdominal pain) and non-serious, and withdrawals were not related to the study treatment. AUTHORS' CONCLUSIONS: We found very few studies that adequately test biotic supplementation as alternative treatments for improving kidney function, GI symptoms, dialysis outcomes, allograft function, patient-reported outcomes, CVD, cancer, reducing uraemic toxins, and adverse effects. We are not certain whether synbiotics, prebiotics, or probiotics are more or less effective compared to one another, antibiotics, or standard care for improving patient outcomes in people with CKD. Adverse events were uncommon and mild.

Multicentre registry analysis of incremental peritoneal dialysis incidence and associations with patient outcomes.

BACKGROUND: Incremental peritoneal dialysis (PD) is increasingly advocated to reduce treatment burden and costs, with potential to better preserve residual kidney function. Global prevalence of incremental PD use is unknown and use in Australia and New Zealand has not been reported. METHODS: Binational registry analysis including incident adult PD patients in Australia and New Zealand (2007-2017), examining incidence of and outcomes associated with incremental PD (first recorded PD exchange volume <42 L/week (incremental) vs. ≥42 L/week (standard)). RESULTS: Incremental PD use significantly increased from 2.7% of all incident PD in 2007 to 11.1% in 2017 (mean increase 0.84%/year). Duration of incremental PD use was 1 year or less in 67% of cases. Male sex, Aboriginal and Torres Strait Islander (ATSI) or Maori ethnicities, age 45-59 years, medical comorbidities or treatment at a centre with low use of automated PD or icodextrin was associated with lower incidence of incremental PD use. Low body mass index and higher estimated glomerular filtration rate was associated with higher incidence. After accounting for patient and centre variables, commencing PD with an incremental prescription was associated with reduced peritonitis risk (adjusted hazard ratio 0.73, 95% confidence interval (CI) 0.61-0.86).When kidney transplantation and death were considered as competing risks, the association between incremental PD and peritonitis was not significant (sub-hazard ratio [SHR] 0.91, 95%CI 0.71-1.17, p = 0.5), however cumulative incidence of 30-day transfer to haemodialysis was lower in those receiving incremental PD (SHR 0.73, 95%CI 0.56-0.94, p = 0.01). There was no association between incremental PD and death. CONCLUSIONS: Incremental PD use is increasing in Australia and New Zealand and is not associated with patient harm.

Participant Perceptions in a Long-term Clinical Trial of Autosomal Dominant Polycystic Kidney Disease.

Rationale & Objective: The development of new therapies for autosomal dominant polycystic kidney disease requires clinical trials to be conducted efficiently. In this study, the factors affecting the recruitment and retention of participants enrolled in a 3-year randomized controlled trial in autosomal dominant polycystic kidney disease were investigated. Study Design: Qualitative study. Setting & Participants: All participants (N=187) were invited to complete a 16-item questionnaire at the final study visit of the primary trial. Participants were recruited to complete a semistructured interview using purposeful sampling according to age, self-reported gender, and randomization group. Analytical Approach: Descriptive statistics were used for demographic data and questionnaires. The interview transcripts underwent inductive thematic coding. Results: One hundred and forty-six of the 187 randomized participants (79%) completed the post-trial questionnaire, and 31 of the 187 participants (21%) completed the interview. Most participants (94%) rated their global satisfaction with the trial as high (a score of 8 or more out of 10). Altruism, knowledge gain, and access to new treatments were the main motivators for recruitment. The main reasons for considering leaving the study were concerns about the risk of intervention and family or work issues. Strategies that favored retention included flexibility in attending different study sites, schedule flexibility, staff interactions, and practical support with parking and reminders. The main burden was time away from work with lost wages, and burden associated with magnetic resonance imaging scans and 24-hour urine output collections. Limitations: The study population was restricted to participants in a single nondrug clinical trial, and the results could be influenced by selection and possible social desirability bias. Conclusions: Participants reported high levels of satisfaction that occurred as a function of the trial meeting participants' expectations. Furthermore, retention was a balance between the perceived benefits and burden of participation. Consideration of these perspectives in the design of future clinical trials will improve their efficiency and conduct. Plain-Language Summary: Advances in the clinical practice of autosomal dominant polycystic kidney disease (ADPKD) require affected individuals to voluntarily participate in long-term multicenter randomized controlled trials (RCTs). In this qualitative post hoc study of a 3-year RCT of increased water intake in ADPKD, altruism, knowledge gain, and access to a nondrug treatment positively influenced the decision to volunteer. Ongoing participation was enabled by building flexibility into the study protocol and staff prioritizing a participant's needs during study visits. Although participants completed the required tests, most were considered burdensome. This study highlights the importance of incorporating protocol flexibility into trial design; the preference for interventions with a low risk of adverse effects; and the urgent requirement for robust surrogate noninvasive biomarkers to enable shorter RCTs in ADPKD.

Association of Incremental peritoneal dialysis with residual kidney function decline in patients on peritoneal dialysis: The balANZ trial.

BACKGROUND: Incremental peritoneal dialysis (PD), defined as less than Full-dose PD prescription, has several possible merits, including better preservation of residual kidney function (RKF), lower peritoneal glucose exposure and reduced risk of peritonitis. The aims of this study were to analyse the association of Incremental and Full-dose PD strategy with RKF and urine volume (UV) decline in patients commencing PD. METHODS: Incident PD patients who participated in the balANZ randomised controlled trial (RCT) (2004-2010) and had at least one post-baseline RKF and UV measurement was included in this study. Patients receiving <56 L/week and ≥56 L/week of PD fluid at PD commencement were classified as Incremental and Full-dose PD, respectively. An alternative cut-point of 42 L/week was used in a sensitivity analysis. The primary and secondary outcomes were changes in measured RKF and daily UV, respectively. RESULTS: The study included 154 patients (mean age 57.9 ± 14.1 years, 44% female, 34% diabetic, mean follow-up 19.5 ± 6.6 months). Incremental and Full-dose PD was commenced by 45 (29.2%) and 109 (70.8%) participants, respectively. RKF declined in the Incremental group from 7.9 ± 3.2 mL/min/1.73 m2 at baseline to 3.2 ± 2.9 mL/min/1.73 m2 at 24 months (p < 0.001), and in the Full-dose PD group from 7.3 ± 2.7 mL/min/1.73 m2 at baseline to 3.4 ± 2.8 mL/min/1.73 m2 at 24 months (p < 0.001). There was no difference in the slope of RKF decline between Incremental and Full-dose PD (p = 0.78). UV declined from 1.81 ± 0.73 L/day at baseline to 0.64 ± 0.63 L/day at 24 months in the Incremental PD group (p < 0.001) and from 1.38 ± 0.61 L/day to 0.71 ± 0.46 L/day in the Full-dose PD group (p < 0.001). There was no difference in the slope of UV decline between Incremental and Full-dose PD (p = 0.18). CONCLUSIONS: Compared with Full-dose PD start, Incremental PD start is associated with similar declines in RKF and UV.

Incidence of Thromboembolic Complications Following Kidney Transplantation with Short and Extended Aspirin Prophylaxis: A Retrospective Single-Center Study.

BACKGROUND Aspirin prophylaxis has been associated with reduced graft-related thrombosis following kidney transplantation. Aspirin cessation, however, can increase risk of venous thromboembolic complications, including pulmonary thromboembolism and deep venous thrombosis. This single-center, retrospective, pre-post interventional study from Brisbane, Australia, aimed to compare the rate of thrombotic complications in 1208 adult kidney transplant recipients receiving postoperative aspirin for 5 days or >6 weeks. MATERIAL AND METHODS We enrolled1208 kidney transplant recipients who received 100 mg aspirin for 5 days (n=571) or >6 weeks (n=637) postoperatively. The primary outcome was venous thromboembolism (VTE) in the first 6 weeks after transplant, examined by multivariable logistic regression analysis. Secondary outcomes were renal vein/artery thrombosis, 1-month serum creatinine, rejection, myocardial infarction, stroke, blood transfusion, dialysis at day 5 and day 28, and mortality. RESULTS Sixteen (1.3%) patients experienced VTE (5-day n=8, 1.4%; >6-week n=8, 1.3%; P=0.8). Extended aspirin duration was not independently associated with a reduction in VTE (OR 0.91, 95% CI 0.32-2.57; P=0.9). Graft thrombosis was rare (n=3, 0.25%). Aspirin duration was not associated with cardiovascular events, blood transfusion, graft thrombosis, graft dysfunction, rejection, or mortality. VTE was independently associated with older age (OR 1.09, 95% CI 1.04-1.16; P=0.002), smoking (OR 3.59, 95% CI 1.20-13.2; P=0.032), younger donor age (OR 0.96, 95% CI 0.93-1.00; P=0.036), and thymoglobulin use (OR 10.5, 95% CI 3.09-32.1; P≥0.001). CONCLUSIONS Extended-duration aspirin use did not significantly reduce the incidence of VTE in the first 6 weeks following kidney transplantation. An association was identified between anti-human thymocyte immunoglobulin and VTE, which requires further assessment.