Journey to kidney transplantation: patient dynamics, suspensions, transplantation and deaths in the Australian kidney transplant waitlist

BACKGROUND AND HYPOTHESIS

People on the kidney waitlist are less informed about potential suspensions. Disparities may exist among those who are suspended and who return to the waitlist. We evaluated the patient journey after entering the waitlist, including suspensions and outcomes, and factors associated with these transitions.

METHODS

We included all incident patients waitlist for their first transplant from deceased donors in Australia, 2006-19. We described all clinical transitions after entering the waitlist. We predicted the restricted mean survival time (unadjusted and adjusted) until first transplant by number of prior suspensions. We evaluated factors associated with transitions using flexible survival models and clinical endpoints using Cox models.

RESULTS

Of 8 466 patients waitlisted and followed over 45 757.4 person-years (median:4.8years), 6 741(80%) were transplanted, 381(5%) died waiting and 1 344(16%) were still waiting. 3 127(37%) people were suspended at least once. Predicted mean time from waitlist to transplant was 3.0 years(95%CI:2.8-3.2) when suspended versus 1.9 years(95%CI:1.8-1.9) when never suspended. Prior suspension increased likeliness of further suspensions 4.2-fold(95%CI:3.8-4.6) and returning to waitlist by 50%(95%CI:36-65%) but decreased likeliness of transplantation by 29%(95%CI:62-82%). Death risk while waiting was 12-fold(95%CI:8.0-18.3) increased when currently suspended. Australian non-Indigenous males were 13% (HR:1.13,95%CI:1.04-1.23) and Asian males 23% (HR:1.23,95%CI:1.06-1.42,) more likely to return to the waitlist compared to females of the same ethnicity.

CONCLUSION

The waitlist journey was not straightforward. Suspension was common, impacted chance of transplantation and meant waiting an average one year longer until transplant. We have provided estimates for, and factors associated with, suspension, re-listing and outcomes after waitlisting to support more informed discussions. This evidence is critical to further understand drivers of inequitable access to transplantation.

Sex differences in associations between creatinine and cystatin C-based kidney function measures with stroke and major bleeding

PURPOSE

We sought to explore whether adding kidney function biomarkers based on creatinine (eGFRCr), cystatin C (eGFRCys) or a combination of the two (eGFRCr-Cys) could improve risk stratification for stroke and major bleeding, and whether there were sex differences in any additive value of kidney function biomarkers.

METHOD

We included participants from the UK Biobank who had not had a previous ischaemic or haemorrhagic stroke or major bleeding episode, and who had kidney function measures available at baseline. Cause-specific Cox proportional hazards models tested associations between eGFRCr, eGFRCys and eGFRCr-Cys (mL/min/1.73 m2) with ischaemic and haemorrhagic stroke, major bleeding (gastrointestinal or intracranial, including haemorrhagic stroke) and all-cause mortality.

FINDINGS

Among 452,879 eligible participants, 246,244 (54.4%) were women. Over 11.5 (IQR 10.8-12.2) years, there were 3706 ischaemic strokes, 795 haemorrhagic strokes, 26,025 major bleeding events and 28,851 deaths. eGFRCys was more strongly associated with ischaemic stroke than eGFRCr: an effect that was more pronounced in women (men - HR: 1.16, 95% CI: 1.12-1.19; female to male comparison - HR: 1.11, 95% CI: 1.05-1.16, per 10 mL/min/1.73 m2 decline in eGFRCys). This interaction effect was also demonstrated for eGFRCr-Cys, but not eGFRCr. eGFRCys and eGFRCr-Cys were more strongly associated with major bleeding and all-cause mortality than eGFRCr in both men and women. Event numbers were small for haemorrhagic stroke.

DISCUSSION

To a greater degree than is seen in men, eGFRCr underestimates risk of ischaemic stroke and major bleeding in women compared to eGFRCys. The difference between measures is likely explained by non-GFR biology of creatinine and cystatin C.

CONCLUSION

Enhanced measurement of cystatin C may improve risk stratification for ischaemic stroke and major bleeding and clinical treatment decisions in a general population setting, particularly for women.

Life Years Lost in Children with Kidney Failure: A Binational Cohort Study with Multistate Probabilities of Death and Life Expectancy

SIGNIFICANCE STATEMENT

In children with kidney failure, little is known about their treatment trajectories or the effects of kidney failure on lifetime survival and years of life lost, which are arguably more relevant measures for children. In this population-based cohort study of 2013 children who developed kidney failure in Australia and New Zealand, most children were either transplanted after initiating dialysis (74%) or had a preemptive kidney transplant (14%). Life expectancy increased with older age at kidney failure, but more life years were spent on dialysis than with a functioning transplant. The expected (compared with the general population) number of life years lost ranged from 16 to 32 years, with female patients and those who developed kidney failure at a younger age experiencing the greatest loss of life years.

BACKGROUND

Of the consequences of kidney failure in childhood, those rated as most important by children and their caregivers are its effects on long-term survival. From a life course perspective, little is known about the experience of kidney failure treatment or long-term survival.

METHODS

To determine expected years of life lost (YLL) and treatment trajectory for kidney failure in childhood, we conducted a population-based cohort study of all children aged 18 years or younger with treated kidney failure in Australia (1980-2019) and New Zealand (1988-2019).We used patient data from the CELESTIAL study, which linked the Australian and New Zealand Dialysis and Transplant registry with national death registers. We estimated standardized mortality ratios and used multistate modeling to understand treatment transitions and life expectancy.

RESULTS

A total of 394 (20%) of 2013 individuals died over 30,082 person-years of follow-up (median follow-up, 13.1 years). Most children (74%) were transplanted after initiating dialysis; 14% (18% of male patients and 10% of female patients) underwent preemptive kidney transplantation. Excess deaths (compared with the general population) decreased dramatically from 1980 to 1999 (from 41 to 22 times expected) and declined more modestly (to 17 times expected) by 2019. Life expectancy increased with older age at kidney failure, but more life years were spent on dialysis than with a functioning transplant. The number of YLL ranged from 16 to 32 years, with the greatest loss among female patients and those who developed kidney failure at a younger age.

CONCLUSIONS

Children with kidney failure lose a substantial number of their potential life years. Female patients and those who develop kidney failure at younger ages experience the greatest burden.

Cost-effectiveness of Interventions to Increase Utilization of Kidneys From Deceased Donors With Primary Brain Malignancy in an Australian Setting

Kidneys from potential deceased donors with brain cancer are often foregone due to concerns of cancer transmission risk to recipients. There may be uncertainty around donors' medical history and their absolute transmission risk or risk-averse decision-making among clinicians. However, brain cancer transmissions are rare, and prolonging waiting time for recipients is harmful.

Methods

We assessed the cost-effectiveness of increasing utilization of potential deceased donors with brain cancer using a Markov model simulation of 1500 patients waitlisted for a kidney transplant, based on linked transplant registry data and with a payer perspective (Australian government). We estimated costs and quality-adjusted life-years (QALYs) for three interventions: decision support for clinicians in assessing donor risk, improved cancer classification accuracy with real-time data-linkage to hospital records and cancer registries, and increased risk tolerance to allow intermediate-risk donors (up to 6.4% potential transmission risk).

Results

Compared with current practice, decision support provided 0.3% more donors with an average transmission risk of 2%. Real-time data-linkage provided 0.6% more donors (1.1% average transmission risk) and increasing risk tolerance (accepting intermediate-risk 6.4%) provided 2.1% more donors (4.9% average transmission risk). Interventions were dominant (improved QALYs and saved costs) in 78%, 80%, and 87% of simulations, respectively. The largest benefit was from increasing risk tolerance (mean +18.6 QALYs and AU$2.2 million [US$1.6 million] cost-savings).

Conclusions

Despite the additional risk of cancer transmission, accepting intermediate-risk donors with brain cancer is likely to increase the number of donor kidneys available for transplant, improve patient outcomes, and reduce overall healthcare expenditure.

AcceSS and Equity in Transplantation (ASSET) New Zealand: Protocol for population-wide data linkage platform to investigate equity in access to kidney failure health services in New Zealand

Background

Kidney transplantation is considered the ideal treatment for most people with kidney failure, conferring both survival and quality of life advantages, and is more cost effective than dialysis. Yet, current health systems may serve some people better than others, creating inequities in access to kidney failure treatments and health outcomes. AcceSS and Equity in Transplantation (ASSET) investigators aim to create a linked data platform to facilitate research enquiry into equity of health service delivery for people with kidney failure in New Zealand.

Methods

The New Zealand Ministry of Health will use patients’ National Health Index (NHI) numbers to deterministically link individual records held in existing registry and administrative health databases in New Zealand to create the data platform. The initial data linkage will include a study population of incident patients captured in the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA), New Zealand Blood Service Database and the Australia and New Zealand Living Kidney Donor Registry (ANZLKD) from 2006 to 2019 and their linked health data. Health data sources will include National Non-Admitted Patient Collection Data, National Minimum Dataset, Cancer Registry, Programme for the Integration of Mental Health Data (PRIMHD), Pharmaceutical Claims Database and Mortality Collection Database. Initial exemplar studies include 1) kidney waitlist dynamics and pathway to transplantation; 2) impact of mental illness on accessing kidney waitlist and transplantation; 3) health service use of living donors following donation.

Conclusion

The AcceSS and Equity in Transplantation (ASSET) linked data platform will provide opportunity for population-based health services research to examine equity in health care delivery and health outcomes in New Zealand. It also offers potential to inform future service planning by identifying where improvements can be made in the current health system to promote equity in access to health services for those in New Zealand.

Notifiable Infectious Diseases Among Organ Transplant Recipients: A Data-Linked Cohort Study, 2000–2015

Background

Infections, including common communicable infections such as influenza, frequently cause disease after organ transplantation, although the quantitative extent of infection and disease remains uncertain.

Methods

A cohort study was conducted to define the burden of notifiable infectious diseases among all solid organ recipients transplanted in New South Wales, Australia, 2000–2015. Data linkage was used to connect transplant registers to hospital admissions, notifiable diseases, and the death register. Standardized incidence ratios (SIRs) were calculated relative to general population notification rates, accounting for age, sex, and calendar year. Infection-related hospitalizations and deaths were identified.

Results

Among 4858 solid organ recipients followed for 39 183 person-years (PY), there were 792 notifications. Influenza was the most common infection (532 cases; incidence, 1358 [95% CI, 1247–1478] per 100 000 PY), highest within 3 months posttransplant. Next most common was salmonellosis (46 cases; incidence, 117 [95% CI, 87–156] per 100 000 PY), then pertussis (38 cases; incidence, 97 [95% CI, 71–133] per 100 000 PY). Influenza and invasive pneumococcal disease (IPD) showed significant excess cases compared with the general population (influenza SIR, 8.5 [95% CI, 7.8–9.2]; IPD SIR, 9.8 [95% CI, 6.9–13.9]), with high hospitalization rates (47% influenza cases, 68% IPD cases) and some mortality (4 influenza and 1 IPD deaths). By 10 years posttransplant, cumulative incidence of any vaccine-preventable disease was 12%, generally similar by transplanted organ, except higher among lung recipients. Gastrointestinal diseases, tuberculosis, and legionellosis had excess cases among transplant recipients, although there were few sexually transmitted infections and vector-borne diseases.

Conclusions

There is potential to avoid preventable infections among transplant recipients with improved vaccination programs, health education, and pretransplant donor and recipient screening.

Sex-Based Differences in Risk Factors and Complications of Chronic Kidney Disease

Globally, females are ∼30% more likely to have pre-dialysis chronic kidney disease (CKD) than males for reasons that are not fully understood. CKD is associated with numerous adverse health outcomes which makes understanding and working to eradicating sex based disparities in CKD prevalence essential. This review maps both what is known, and what is unknown, about the way sex and gender impacts (1) the epidemiology and risk factors for CKD including age, diabetes, hypertension, obesity, smoking, and cerebrovascular disease, and (2) the complications from CKD including kidney disease progression, cardiovascular disease, CKD mineral and bone disorders, anaemia, quality-of-life, cancer and mortality. This mapping can be used to guide future research.

Characteristics and Donation Outcomes of Potential Organ Donors Perceived to Be at Increased Risk for Blood-borne Virus Transmission: An Australian Cohort Study 2010-2018

BACKGROUND

Safely increasing organ donation to meet need is a priority. Potential donors may be declined because of perceived blood-borne virus (BBV) transmission risk. With hepatitis C (HCV) curative therapy, more potential donors may now be suitable. We sought to describe potential deceased donors with increased BBV transmission risk.

METHODS

We conducted a cohort study of all potential organ donors referred in NSW, Australia, 2010-2018. We compared baseline risk potential donors to potential donors with increased BBV transmission risk, due to history of HIV, HCV or hepatitis B, and/or behavioral risk factors.

RESULTS

There were 624 of 5749 potential donors (10.9%) perceived to have increased BBV transmission risk. This included 298 of 5749 (5.2%) with HCV (including HBV coinfections) and 239 of 5749 (4.2%) with increased risk behaviors (no known BBV). Potential donors with HCV and those with increased risk behaviors were younger and had fewer comorbidities than baseline risk potential donors (P < 0.001). Many potential donors (82 with HCV, 38 with risk behaviors) were declined for donation purely because of perceived BBV transmission risk. Most were excluded before BBV testing. When potential donors with HCV did donate, they donated fewer organs than baseline risk donors (median 1 versus 3, P < 0.01), especially kidneys (odds ratio 0.08, P < 0.001) and lungs (odds ratio 0.11, P = 0.006).

CONCLUSIONS

Many potential donors were not accepted because of perceived increased BBV transmission risk, without viral testing, and despite otherwise favorable characteristics. Transplantation could be increased from potential donors with HCV and/or increased risk behaviors.

Epidemiology of cardiovascular death in kidney failure: An Australian and New Zealand cohort study using data linkage

Aim

Cardiovascular mortality risk evolves over the lifespan of kidney failure (KF), as patients develop comorbid disease and transition between treatment modalities. Absolute cardiovascular death rates would help inform clinical practice and health‐care provision, but are not well understood across a continuum of dialysis and transplant states. We aimed to characterize cardiovascular death across the natural history of KF using a lifespan approach.

Methods

We performed a population‐based cohort study of incident patients commencing kidney replacement therapy in Australia and New Zealand. Cardiovascular deaths were identified using data linkage to national death registers. We estimated the probability of death and kidney transplant using multi‐state models, and calculated rates of graft failure and cardiovascular death across demographic factors and comorbidities.

Results

Among 60 823 incident patients followed over 381 874 person‐years, 25% (8492) of deaths were from cardiovascular disease. At 15 years from treatment initiation, patients had a 15.2% probability of cardiovascular death without being transplanted, but only 2.3% probability of cardiovascular death post‐transplant. Females had a 3% lower probability of cardiovascular death at 15 years (15.3% vs. 18.6%) but 4% higher probability of non‐cardiovascular death (54.5% vs. 50.8%). Within the first year of dialysis, cardiovascular mortality peaked in the second month and showed little improvement across treatment era.

Conclusion

Despite improvements over time, cardiovascular death remains common in KF, particularly among the dialysis population and in the first few months of treatment. Multi‐state models can provide absolute measures of cardiovascular mortality across both dialysis and transplant states.

In this population‐based cohort study using multi‐state models (alive without kidney transplant [KT], CV death without KT, non‐CV death without KT, alive after first KT, CV death after first KT and non‐CV death after first KT), the probability of CV death was higher in non‐KT than KT patients at 15 years from treatment. In patients on dialysis, CV mortality was highest from the second month after commencing dialysis and remained high thereafter. Thus, the use of multi‐state models provides helpful information on impacts of different treatments with respect to serious outcomes.

Sex differences in mortality among binational cohort of people with chronic kidney disease: population based data linkage study

OBJECTIVE

To evaluate sex differences in mortality among people with kidney failure compared with the general population.

DESIGN

Population based cohort study using data linkage.

SETTING

The Australian and New Zealand Dialysis and Transplant Registry (ANZDATA), which includes all patients receiving kidney replacement therapy in Australia (1980-2019) and New Zealand (1988-2019). Data were linked to national death registers to determine deaths and their causes, with additional details obtained from ANZDATA.

PARTICIPANTS

Of 82 844 people with kidney failure, 33 329 were female (40%) and 49 555 were male (60%); 49 376 deaths (20 099 in female patients; 29 277 in male patients) were recorded over a total of 536 602 person years of follow-up.

MAIN OUTCOME MEASURES

Relative measures of survival, including standardised mortality ratios, relative survival, and years of life lost, using general population data to account for background mortality (adjusting for country, age, sex, and year). Estimates were stratified by dialysis modality (haemodialysis or peritoneal dialysis) and for the subpopulation of kidney transplant recipients.

RESULTS

Few differences in outcomes were found between male and female patients with kidney failure. However, compared with the general population, female patients with kidney failure had greater excess all cause deaths than male patients (female patients: standardised mortality ratio 11.3, 95% confidence interval 11.2 to 11.5, expected deaths 1781, observed deaths 20 099; male patients: 6.9, 6.8 to 6.9, expected deaths 4272, observed deaths 29 277). The greatest difference was observed among younger patients and those who died from cardiovascular disease. Relative survival was also consistently lower in female patients, with adjusted excess mortality 11% higher (95% confidence interval 8% to 13%). Average years of life lost was 3.6 years (95% confidence interval 3.6 to 3.7) greater in female patients with kidney failure compared with male patients across all ages. No major differences were found in mortality by sex for haemodialysis or peritoneal dialysis. Kidney transplantation reduced but did not entirely remove the sex difference in excess mortality, with similar relative survival (P=0.83) and years of life lost difference reduced to 2.3 years (95% confidence interval 2.2 to 2.3) between female and male patients.

CONCLUSIONS

Compared with the general population, female patients had greater excess deaths, worse relative survival, and more years of life lost than male patients, however kidney transplantation reduced these differences. Future research should investigate whether systematic differences exist in access to care and possible strategies to mitigate excess mortality among female patients.

Cancer transmissions and non-transmissions from solid organ transplantation in an Australian cohort of deceased and living organ donors

Evidence on cancer transmission from organ transplantation is poor. We sought to identify cases of cancer transmission or non-transmission from transplantation in an Australian cohort of donors and recipients. We included NSW solid organ deceased donors 2000-2012 and living donors 2004-2012 in a retrospective cohort using linked data from the NSW Biovigilance Register (SAFEBOD). Central Cancer Registry (CCR) data 1972-2013 provided a minimum one-year post-transplant follow-up. We identified cancers in donors and recipients. For each donor-recipient pair, the transmission was judged likely, possible, unlikely, or excluded using categorization from international guidelines. In our analysis, transmissions included those judged likely, while those judged possible, unlikely, or excluded were non-transmissions. In our cohort, there were 2502 recipients and 1431 donors (715 deceased, 716 living). There were 2544 transplant procedures, including 1828 (72%) deceased and 716 (28%) living donor transplants. Among 1431 donors, 38 (3%) had past or current cancer and they donated to 68 recipients (median 6.7-year follow-up). There were 64 (94%) non-transmissions, and 4 (6%) transmissions from two living and two deceased donors (all kidney cancers discovered during organ recovery). Donor transmitted cancers are rare, and selected donors with a past or current cancer may be safe for transplantation.

Cause of death for people with end-stage kidney disease withdrawing from treatment in Australia and New Zealand

BACKGROUND

Withdrawal from renal replacement therapy is common in patients with end-stage kidney disease (ESKD), but end-of-life service planning is challenging without population-specific data. We aimed to describe mortality after treatment withdrawal in Australian and New Zealand ESKD patients and evaluate death-certified causes of death.

METHODS

We performed a retrospective cohort study on incident patients with ESKD in Australia, 1980-2013, and New Zealand, 1988-2012, from the Australian and New Zealand Dialysis and Transplant registry. We estimated mortality rates (by age, sex, calendar year and country) and summarized withdrawal-related deaths within 12 months of treatment modality change. Certified causes of death were ascertained from data linkage with the Australian National Death Index and New Zealand Mortality Collection database.

RESULTS

Of 60 823 patients with ESKD, there were 8111 treatment withdrawal deaths and 26 207 other deaths over 381 874 person-years. Withdrawal-related mortality rates were higher in females and older age groups. Rates increased between 1995 and 2013, from 1142 (95% confidence interval 1064-1226) to 2706/100 000 person-years (95% confidence interval 2498-2932), with the greatest increase in 1995-2006. A third of withdrawal deaths occurred within 12 months of treatment modality change. The national death registers reported kidney failure as the underlying cause of death in 20% of withdrawal cases, with other causes including diabetes (21%) and hypertensive disease (7%). Kidney disease was not mentioned for 18% of withdrawal patients.

CONCLUSIONS

Treatment withdrawal represents 24% of ESKD deaths and has more than doubled in rate since 1988. Population data may supplement, but not replace, clinical data for end-of-life kidney-related service planning.

Cardiac Mortality in Kidney Transplant Patients: A Population-based Cohort Study 1988-2013 in Australia and New Zealand

BACKGROUND

Transplant recipients experience excess cardiac mortality. We compared circulatory death rates in Australian and New Zealand kidney transplant recipients to the general population and identified risk factors for circulatory death in kidney transplant recipients.

METHODS

The primary cause of death for kidney transplant recipients aged ≥18 was established through ICD-10-AM codes using data linkage between the Australia and New Zealand dialysis and transplant registry and national death registers. We estimated standardized mortality ratios (SMRs) and developed a Fine-Gray competing risks model to determine risk factors for cardiac mortality.

RESULTS

Of 5089 deaths in 16 329 kidney transplant recipients (158 325 person-years), 918 (18%) were cardiac. An increased risk of circulatory death was associated with older age (P < 0.001), male sex (P < 0.001), longer dialysis duration (P = 0.004), earlier era of transplantation (P < 0.001), ever graft failure (P < 0.001), known coronary artery disease (P = 0.002), and kidney failure from diabetes or hypertension (P < 0.001). The cardiac SMR was 5.4 [95% confidence interval (CI): 5.0-5.8], falling from 8.0 (95% CI: 4.9-13.1) in 1988 to 5.3 (95% CI: 4.0-7.0) in 2013 (P < 0.001). Females, particularly young ones, had significantly higher relative cardiac mortality than men. In recipients aged 40 years, the cardiac SMR was 26.5 (95% CI: 15.0-46.6) in females and 7.5 (95% CI: 5.0-11.1) for males.

CONCLUSIONS

Cardiac risks remain elevated in kidney transplant recipients and may be under-recognized, and prevention and treatment interventions less accessed, less effective or even harmful in female recipients.

Sex Differences in Mortality Among People with End-Stage Kidney Disease: Bi-National Data-Linkage Cohort Study

IntroductionFemale life expectancies consistently exceed males in the general population. Yet, this survival advantage may not persist in the presence of a chronic disease due to biological differences or healthcare inequities. Objectives and ApproachWe aimed to explore sex differences in mortality among people with end-stage kidney disease (ESKD). T he entire ESKD population in Australia, 1980-2013, and New Zealand,1988-2012, were included from the Australian and New Zealand Dialysis and Transplant Registry. Data linkage to national death registers was undertaken to ascertain deaths and their causes. We estimated relative measures of survival, including standardized mortality ratios (SMR), relative survival and expected life years lost, using general population data to account for background mortality, adjusting for country, age, sex and year. ResultsOf 60,823 ESKD patients, there were 25,042 females (41%) and 35,781 males (59%). Mortality sex differences within the ESKD population were minor, but once compared to the general population, female ESKD patients had more excess deaths, worse relative survival and greater life years lost compared to male ESKD patients. Females had 11.5 SMR (95%CI:11.3-11.7) and males had 6.7 SMR (95%CI:6.7-6.8), with greater disparity among younger ages and from certain causes. Relative survival was consistently lower in females, with adjusted excess mortality 9% higher (95%CI:7-12%) in ESKD females. Average life years lost was 4-5 years greater in ESKD females compared to males across all ages. Kidney transplantation reduced the sex differences in excess mortality, with similar relative survival (p=0.42) and average life years lost reduced to 3-4 years for females. Conclusion / ImplicationsThe impact of ESKD is more profound for women than men with greater excess mortality, however kidney transplantation attenuates these differences. Our findings show that chronic diseases and sex can compound to produce worse outcomes where women lose their survival advantage in the presence of ESKD.

Vaccine-Preventable Infections Among Solid Organ Transplant Recipients: A Data-Linked Cohort Study, Australia, 2000-2015

IntroductionRecipients of solid organ transplants are at risk of serious infection due to immunosuppression. Some infections are preventable with vaccination; infection rates vary with immunosuppression, vaccination rates and baseline disease prevalence. Both adherence with and response to vaccination in this population are variable, and optimum vaccination strategies continue to be refined. Objectives and ApproachWe aimed to characterise the incidence and complications of vaccine-preventable infections in transplant recipients. Eligible participants received an organ transplant in New South Wales, Australia, in 2000-2015. Linkage was undertaken between transplant registries and the notifiable conditions information management system. Vaccine-preventable infections were diphtheria, Haemophilus influenzae type b, influenza, invasive pneumococcal disease, measles, mumps, pertussis, poliovirus, rubella and tetanus. Standardized incidence ratios (SIR) were calculated relative to Australian population notification rates, standardizing for gender, age and calendar year. ResultsAmong 3,394 recipients, 399 vaccine-preventable infections affected 339 (10%) recipients. Influenza was the most common vaccine-preventable infection with 352 notifications among 305 recipients. Influenza cases were 8.9 times more common among transplant recipients than the general population (95%CI: 8.0-10.0). In 36 cases (10%), hospitalization was required, and 2 deaths due to influenza were reported. There were 20 notifications of invasive pneumococcal disease (IPD) for 18 recipients. IPD occurred 10.2 times more often among transplant recipients than the general population (95%CI: 6.4-16.2). Most (n=13, 65%) cases were hospitalized, and one patient died from IPD. Cases of pertussis occurred only slightly more often than in the general population (SIR 1.5, 95%CI: 1.0-2.3). Of 26 cases, there was one reported hospitalization and no deaths due to pertussis. Only one case of mumps, and no other vaccine-preventable infections, were reported. ConclusionTransplant recipients have excess cases of influenza and IPD compared to the general population, although this has improved over time. The need for appropriate recipient vaccination is emphasized.

New Blood Borne Virus Infections Among Organ Transplant Recipients: A Data-Linked Cohort Study Examining Transmissions and De Novo Infections

IntroductionSolid organ transplant recipients are at risk of infections, which may be either derived through transplantation or acquired later. Blood-borne viruses (BBV) are a particular concern for donor-derived transmissions. There is an increasing emphasis on biovigilance – monitoring the safety of donated organs. However, systematic surveillance to distinguish donor-transmitted infection from de novo post-transplant infection is challenging. Additional information can be obtained through linkage of administrative health data. Objectives and ApproachWe aimed to identify donor-transmitted and de novo BBV infections among organ transplant recipients. We conducted a cohort study of all solid organ donor-recipient pairs in New South Wales, Australia, 2000-2015. Donor and recipient BBV infections were identified by linking transplant registries with administrative health data. Proven/probable donor-transmissions were identified among new recipient infections within 12 months of transplant, classified according to an international algorithm. All other new BBV infections were classified as de novo infections. ResultsAmong 2,120 organ donors, 73 had a BBV infection (11/73 active, 62/73 past). Donors with BBV donated to 176 recipients, of whom 24/176 had the same BBV as their donor, and 152/176 did not; these 152 recipients were at risk of donor-transmission. Among those at risk, there were 3/152 proven/probable BBV transmissions (1 hepatitis C, 2 hepatitis B [HBV]) and 149/152 recipients with non-transmissions. All donor-transmissions were previously recognised by donation services, and were from donors with known BBV. There were no deaths from transmissions. There were 70 recipients with de novo BBV; 2/70 died from new HBV. Conclusion / ImplicationsThis work confirms the safety of Australian organ donation, with no unrecognised BBV transmissions and many non-transmissions from donors with BBV. This may support increasing targeted donation from donors with BBV. However, de novo BBV infections were substantial and preventable. Data-linkage may be a useful adjunct to current biovigilance systems.

New blood-borne virus infections among organ transplant recipients: An Australian data-linked cohort study examining donor transmissions and other HIV, hepatitis C and hepatitis B notifications, 2000-2015

BACKGROUND

Blood-borne viral infections can complicate organ transplantation. Systematic monitoring to distinguish donor-transmitted infections from other new infections post transplant is challenging. Administrative health data can be informative. We aimed to quantify post-transplant viral infections, specifically those transmitted by donors and those reactivating or arising new in recipients.

METHODS

We linked transplant registries with administrative health data for all solid organ donor-recipient pairs in New South Wales, Australia, 2000-2015. All new recipient notifications of hepatitis B (HBV), C (HCV), or human immunodeficiency virus (HIV) after transplant were identified. Proven/probable donor transmissions within 12 months of transplant were classified using an international algorithm.

RESULTS

Of 2120 organ donors, there were 72 with a viral infection (9/72 active, 63/72 past). These 72 donors donated to 173 recipients, of whom 24/173 already had the same infection as their donor, and 149/173 did not, so were at risk of donor transmission. Among those at risk, 3/149 recipients had proven/probable viral transmissions (1 HCV, 2 HBV); none were unrecognized by donation services. There were no deaths from transmissions. There were no donor transmissions from donors without known blood-borne viruses. An additional 68 recipients had new virus notifications, of whom 2/68 died, due to HBV infection.

CONCLUSION

This work confirms the safety of organ donation in an Australian cohort, with no unrecognized viral transmissions and most donors with viral infections not transmitting the virus. This may support targeted increases in donation from donors with viral infections. However, other new virus notifications post transplant were substantial and are preventable. Data linkage can enhance current biovigilance systems.

Effect of language and country of birth on the consent process and medical suitability of potential organ donors; a linked-data cohort study 2010-2015

PURPOSE

Australia has unmet need for transplantation. We sought to assess the impact of cultural and linguistic diversity (CALD) on family consent and medical suitability for organ donation.

METHOD

Cohort study of New South Wales donor referrals, 2010-2015. Logistic regression estimated effects of primary language other than English and birthplace outside Australia (odds ratios OR, with 95% confidence intervals, 95%CI). Outcomes were whether families were asked for consent to donation, provided consent for donation, and whether the referral was medically suitable for donation.

RESULTS

Of 2977 organ donor referrals, a similar proportion of families had consent for donation was sought between non-English speakers and English speakers (p = .07), and between overseas-born compared to Australian-born referrals (p = .3). However, consent was less likely to be given for both non-English speakers than English speakers (OR 0.44, 95%CI:0.29-0.67), and those overseas-born than Australian-born (OR 0.54, 95%CI:0.41-0.72). For referrals both overseas-born and non-English speaking, families were both less likely to be asked for consent (OR 0.67; 95%CI:0.49-0.91) or give consent (OR 0.24; 95%CI0.16-0.37). There was no difference in medical suitability between English speakers and non-English speakers (p = .6), or between Australian-born and overseas-born referrals (p = .6).

CONCLUSION

Intervention to improve consent rates from CALD families may increase donation.

Durability of antiretroviral therapy regimens and determinants for change in HIV-1-infected patients in the TREAT Asia HIV Observational Database (TAHOD-LITE)

BACKGROUND

The durability of first-line regimen is important to achieve long-term treatment success for the management of HIV infection. Our analysis describes the duration of sequential ART regimens and identifies the determinants leading to treatment change in HIV-positive patients initiating in Asia.

METHODS

All HIV-positive adult patients initiating first-line ART in 2003-2013, from eight clinical sites among seven countries in Asia. Patient follow-up was to May 2014. Kaplan-Meier curves were used to estimate the time to second-line ART and third-line ART regimen. Factors associated with treatment durability were assessed using Cox proportional hazards model.

RESULTS

A total of 16,962 patients initiated first-line ART. Of these, 4,336 patients initiated second-line ART over 38,798 person-years (pys), a crude rate of 11.2 (95% CI 10.8, 11.5) per 100 pys. The probability of being on first-line ART increased from 83.7% (95% CI 82.1, 85.1%) in 2003-2005 to 87.9% (95% CI 87.1, 88.6%) in 2010-2013. Third-line ART was initiated by 1,135 patients over 8,078 pys, a crude rate of 14.0 (95% CI 13.3, 14.9) per 100 pys. The probability of continuing second-line ART significantly increased from 64.9% (95% CI 58.5, 70.6%) in 2003-2005 to 86.2% (95% CI 84.7, 87.6%) in 2010-2013.

CONCLUSIONS

Rates of discontinuation of first- and second-line regimens have decreased over the last decade in Asia. Subsequent regimens were of shorter duration compared to the first-line regimen initiated in the same year period. Lower CD4⁺ T-cell count and the use of suboptimal regimens were important factors associated with higher risk of treatment switch.

Residual risk of infection with blood-borne viruses in potential organ donors at increased risk of infection: systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence and incidence of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) among people at increased risk of infection in Australia; to estimate the residual risk of infection among potential solid organ donors in these groups when their antibody and nucleic acid test results are negative.

STUDY DESIGN

Systematic review and meta-analysis of reports of the incidence and prevalence of HIV, HCV, and HBV in groups at increased risk of infection in Australia.

DATA SOURCES

MEDLINE, government and agency reports, Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine conference abstracts, the Australian New Zealand Clinical Trial Registry, and National Health and Medical Research Council grants published 1 January 2000 - 14 February 2019; personal communications.

DATA SYNTHESIS

Residual risk of HIV infection was highest among men who have sex with men (4.8 [95% CI, 2.7-6.9] per 10 000 antibody-negative persons; 1.5 [95% CI, 0.9-2.2] per 10 000 persons who are both antibody- and nucleic acid-negative). Residual risk of HCV infection was highest among injecting drug users (289 [95% CI, 191-385] per 10 000 antibody-negative persons; 20.9 [95% CI, 13.8-28.0] per 10 000 antibody- and nucleic acid-negative persons). Residual risk for HBV infection was highest among injecting drug users (98.6 [95% CI, 36.4-213] per 10 000 antibody-negative people; 49.4 [95% CI, 18.2-107] per 10 000 persons who were also nucleic acid-negative).

CONCLUSIONS

Absolute risks of window period viral infections are low in people from Australian groups at increased risk but with negative viral test results. Accepting organ donations by people at increased risk of infection but with negative viral test results could be considered as a strategy for expanding the donor pool.

REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO), CRD42017069820.

Death From Stroke in End-Stage Kidney Disease

Background and Purpose—

People with end-stage kidney disease (ESKD) are at greater risk of stroke. We aimed to compare stroke mortality between the ESKD population and the general population.

Methods—

We included all patients with incident ESKD in Australia, 1980 to 2013, and New Zealand, 1988 to 2012. The primary cause of death was ascertained using data linkage with national death registers. We produced standardized mortality ratios for stroke deaths, by age, sex, and calendar year.

Results—

We included 60 823 patients with ESKD, where 941 stroke deaths occurred during 381 874 person-years. Patients with ESKD had >3× the stroke deaths compared with the general population (standardized mortality ratio, 3.4; 95% CI, 3.2–3.6), markedly higher in younger people and women. The greatest excess was in intracerebral hemorrhages (standardized mortality ratio, 5.2; 95% CI, 4.5–5.9). Excess stroke deaths in patients with ESKD decreased over time, although were still double in 2013 (2013 standardized mortality ratio, 2.1; 95% CI, 1.5–2.9).

Conclusions—

People with ESKD experience much greater stroke mortality with the greatest difference for women and younger people. However, mortality has improved over time.

Global Trends in CD4 Cell Count at the Start of Antiretroviral Therapy: Collaborative Study of Treatment Programs

Background

Early initiation of combination antiretroviral therapy (cART), at higher CD4 cell counts, prevents disease progression and reduces sexual transmission of human immunodeficiency virus (HIV). We describe the temporal trends in CD4 cell counts at the start of cART in adults from low-income, lower-middle-income, upper-middle-income, and high-income countries (LICs, LMICs, UMICs, and HICs, respectively).

Methods

We included HIV-infected individuals aged ≥16 years who started cART between 2002 and 2015 in a clinic participating in the International epidemiology Databases to Evaluate AIDS (IeDEA) or the Collaboration of Observational HIV Epidemiological Research in Europe (COHERE). Missing CD4 cell counts at the start of cART were estimated through multiple imputation. Weighted mixed-effect models were used to smooth trends in median CD4 cell counts.

Results

A total of 951855 adults from 16 LICs, 11 LMICs, 9 UMICs, and 19 HICs were included. Overall, the modeled median CD4 cell count at the start of cART increased from 2002 to 2015, from 78/µL (95% confidence interval, 58-104/µL) to 287/µL (250-328/µL) in LICs, from 99/µL (71-140/µL) to 234/µL (192-285/µL) in LMICs, from 71/µL (49-104/µL) to 311/µL (255-379/µL) in UMICs, and from 161/µL (143-181/µL) to 327/µL (286-372/µL) in HICs. In LICs, LMICs, and UMICs, the increase was more pronounced in women; in HICs, the opposite was observed.

Conclusions

Median CD4 cell counts at the start of cART increased in all income groups, but generally remained below 350/μL in 2015. Substantial additional efforts and resources are required to achieve earlier diagnosis, linkage to care, and initiation of cART.

Growing challenges for HIV programmes in Asia: clinic population trends, 2003-2013

The scale-up of antiretroviral therapy (ART) has led to a substantial change in the clinical population of HIV-positive patients receiving care. We describe the temporal trends in the demographic and clinical characteristics of HIV-positive patients initiating ART in 2003-13 within an Asian regional cohort. All HIV-positive adult patients that initiated ART between 2003 and 2013 were included. We summarized ART regimen use, age, CD4 cell count, HIV viral load, and HIV-related laboratory monitoring rates during follow-up by calendar year. A total of 16 962 patients were included in the analysis. Patients in active follow-up increased from 695 patients at four sites in 2003 to 11,137 patients at eight sites in 2013. The proportion of patients receiving their second or third ART regimen increased over time (5% in 2003 to 29% in 2013) along with patients aged ≥50 years (8% in 2003 to 18% in 2013). Concurrently, CD4 monitoring has remained stable in recent years, whereas HIV viral load monitoring, although varied among the sites, is increasing. There have been substantial changes in the clinical and demographic characteristics of HIV-positive patients receiving ART in Asia. HIV programmes will need to anticipate the clinical care needs for their aging populations, expanded viral load monitoring, and, the eventual increase in second and third ART regimens that will lead to higher costs and more complex drug procurement needs.

Trends in CD4 cell count response to first-line antiretroviral treatment in HIV-positive patients from Asia, 2003-2013: TREAT Asia HIV Observational Database Low Intensity Transfer

Antiretroviral treatment (ART) guidelines have changed over the past decade, recommending earlier initiation and more tolerable regimens. The study objective was to examine the CD4 response to ART, depending on the year of ART initiation, in HIV-positive patients in the Asia-Pacific. We included HIV-positive adult patients who initiated ART between 2003 and 2013 in our regional cohort from eight urban referral centres in seven countries within Asia. We used mixed-effects linear regression models to evaluate differences in CD4 response by year of ART initiation during 36 months of follow-up, adjusted a priori for other covariates. Overall, 16,962 patients were included. Patients initiating in 2006-9 and 2010-13 had an estimated mean CD4 cell count increase of 8 and 15 cells/µl, respectively, at any given time during the 36-month follow-up, compared to those in 2003-5. The median CD4 cell count at ART initiation also increased from 96 cells/µl in 2003-5 to 173 cells/µl in 2010-13. Our results suggest that the CD4 response to ART is modestly higher for those initiating ART in more recent years. Moreover, fewer patients are presenting with lower absolute CD4 cell counts over time. This is likely to reduce their risk of opportunistic infections and future non-AIDS defining cancers.

A pseudo-random patient sampling method evaluated

OBJECTIVES

To compare two human immunodeficiency virus (HIV) cohorts to determine whether a pseudo-random sample can represent the entire study population.

STUDY DESIGN AND SETTING

HIV-positive patients receiving care at eight sites in seven Asian countries. The TREAT Asia HIV Observational database (TAHOD) pseudo-randomly selected a patient sample, while TREAT Asia HIV Observational database-Low Intensity Transfer (TAHOD-LITE) included all patients. We compared patient demographics, CD4 count, and HIV viral load testing for each cohort. Risk factors associated with CD4 count response, HIV viral load suppression (<400 copies/mL), and survival were determined for each cohort.

RESULTS

There were 2,318 TAHOD patients and 14,714 TAHOD-LITE patients. Patient demographics, CD4 count, and HIV viral load testing rates were broadly similar between the cohorts. CD4 count response and all-cause mortality were consistent among the cohorts with similar risk factors. HIV viral load response appeared to be superior in TAHOD and many risk factors differed, possibly due to viral load being tested on a subset of patients.

CONCLUSION

Our study gives the first empirical evidence that analysis of risk factors for completely ascertained end points from our pseudo-randomly selected patient sample may be generalized to our larger, complete population of HIV-positive patients. However, results can significantly vary when analyzing smaller or pseudo-random samples, particularly if some patient data are not completely missing at random, such as viral load results.

Treatment durability and virological response in treatment-experienced HIV-positive patients on an integrase inhibitor-based regimen: an Australian cohort study

Background: Integrase inhibitors (INSTI) are a newer class of antiretroviral (ARV) drugs that offer additional treatment options for experienced patients. Our aim is to describe treatment durability and virological outcomes in treatment-experienced HIV-positive patients using INSTI-based regimens. Methods: All patients in the Australian HIV Observational Database who had received an INSTI-based regimen ≥ 14 days as well as previous therapy were included in the study. We defined two groups of treatment-experienced patients: (1) those starting a second-line regimen with INSTI; and (2) highly experienced patients, defined as having prior exposure to all three main ARV classes, nucleoside reverse transcriptase inhibitor, nonnucleoside reverse transcriptase inhibitors and protease inhibitors, before commencing INSTI. Survival methods were used to determine time to viral suppression and treatment switch, stratified by patient treatment experience. Covariates of interest included age, gender, hepatitis B and C co-infection, previous antiretroviral treatment time, patient treatment experience and baseline viral load. Results: Time to viral suppression and regimen switching from INSTI initiation was similar for second-line and highly experienced patients. The probability of achieving viral suppression at 6 months was 77.7% for second-line patients and 68.4% for highly experienced patients. There were 60 occurrences of regimen switching away from INSTI observed over 1274.0 person-years, a crude rate of 4.71 (95% CI: 3.66-6.07) per 100 person-years. Patient treatment experience was not a significant factor for regimen switch according to multivariate analysis, adjusting for relevant covariates. Conclusions: We found that INSTI-based regimens were potent and durable in experienced HIV-positive patients receiving treatment outside clinical trials. These results confirm that INSTI-based regimens are a robust treatment option.

Improved survival in HIV treatment programmes in Asia

BACKGROUND

Antiretroviral treatment (ART) for HIV-positive patients has expanded rapidly in Asia over the last 10 years. Our study aimed to describe the time trends and risk factors for overall survival in patients receiving first-line ART in Asia.

METHODS

We included HIV-positive adult patients who initiated ART between 2003-2013 (n=16,546), from seven sites across six Asia-Pacific countries. Patient follow-up was to May 2014. We compared survival for each country and overall by time period of ART initiation using Kaplan-Meier curves. Factors associated with mortality were assessed using Cox regression, stratified by site. We also summarized first-line ART regimens, CD4⁺ T-cell count at ART initiation, and CD4⁺ T-cell and HIV viral load testing frequencies.

RESULTS

There were 880 deaths observed over 54,532 person-years of follow-up, a crude rate of 1.61 (95% CI 1.51, 1.72) per 100 person-years. Survival significantly improved in more recent years of ART initiation. The survival probability at 4 years follow-up for those initiating ART in 2003-2005 was 92.1%, 2006-2009 was 94.3% and 2010-2013 was 94.5% (P<0.001). Factors associated with higher mortality risk included initiating ART in earlier time periods, older age, male sex, injecting drug use as HIV exposure and lower pre-ART CD4⁺ T-cell count. Concurrent with improved survival was increased tenofovir use, ART initiation at higher CD4⁺ T-cell counts and greater monitoring of CD4⁺ T-cells and HIV viral load.

CONCLUSIONS

Our results suggest that HIV-positive patients from Asia have improved survival in more recent years of ART initiation. This is likely a consequence of improvements in treatment, patient management and monitoring over time.

Estimating antiretroviral treatment coverage rates and viral suppression rates for homosexual men in Australia

Gay and other men who have sex with men (GMSM) are disproportionally affected by the HIV epidemic in Australia. The study objective is to combine a clinical-based cohort with a community-based surveillance system to present a broader representation of the GMSM community to determine estimates of proportions receiving antiretroviral therapy (ART) and/or with an undetectable viral load. Between 2010 and 2012, small increases were shown in ART uptake (to 70.2%) and proportions with undetectable viral load (to 62.4%). The study findings highlight the potential for significantly increasing ART uptake among HIV-positive GMSM to reduce the HIV epidemic in Australia.