Secular trends in end-stage renal disease requiring dialysis in Manitoba, Canada: a population-based study

Expanding Access to High KDPI Kidney Transplant for Recipients Aged 60 y and Older: Cost Utility and Survival

Background

Modern organ allocation systems are tasked with equitably maximizing the utility of transplanted organs. Increasing the use of deceased donor organs at risk of discard may be a cost-effective strategy to improve overall transplant benefit. We determined the survival implications and cost utility of increasing the use of marginal kidneys in an older adult Canadian population of patients with end-stage kidney disease.

Methods

We constructed a cost-utility model with microsimulation from the perspective of the Canadian single-payer health system for incident transplant waitlisted patients aged 60 y and older. A kidney donor profile index score of ≥86 was considered a marginal kidney. Donor- and recipient-level characteristics encompassed in the kidney donor profile index and estimated posttransplant survival scores were used to derive survival posttransplant. Patients were followed up for 10 y from the date of waitlist initiation. Our analysis compared the routine use of marginal kidneys (marginal kidney scenario) with the current practice of limited use (status quo scenario).

Results

The 10-y mean cost and quality-adjusted life-years per patient in the marginal kidney scenario were estimated at $379 485.33 (SD: $156 872.49) and 4.77 (SD: 1.87). In the status quo scenario, the mean cost and quality-adjusted life-years per patient were $402 937.68 (SD: $168 508.85) and 4.37 (SD: 1.87); thus, the intervention was considered dominant. At 10 y, 62.8% and 57.0% of the respective cohorts in the marginal kidney and status quo scenarios remained alive.

Conclusions

Increasing the use of marginal kidneys in patients with end-stage kidney disease aged 60 y and older may offer cost savings, improved quality of life, and greater patient survival in comparison with usual care.

Feasibility of Intradialytic Cycling Program in a Remote Community Hemodialysis Unit: Mixed-Methods Analysis of Implementation

BACKGROUND

There is growing evidence demonstrating the benefits of intradialytic cycling. However, there are relatively few centers where this practice has been adopted with no reports from hemodialysis units in rural, remote, and northern locations. Maintaining mobility and quality of life for patients on kidney replacement therapy living in remote northern communities is inhibited by inclement weather and lack of access to resources and infrastructure that support physical activity. The integration of intradialytic cycling during hemodialysis offers patients a form of safe physical activity year-round.

OBJECTIVE

This study focuses on better understanding the feasibility and acceptability of implementing intradialytic cycling in a remote northern geographical context.

DESIGN

A feasibility study using a mixed-methods explanatory design was adopted for this study.

SETTING

The research is conducted in Prince George, British Columbia.

PARTICIPANTS

The participants are patients attending a community-based dialysis unit in remote northern British Columbia and health professionals working in the same facility.

METHODS

Quantitative measures were captured through cycling logbooks and quality of life measure, and qualitative data were obtained through semi-structured interviews and analyzed using thematic analysis.

RESULTS

Six (43%) eligible patients used leg ergometers more than once for a median of 2.5 (interquartile range: 1-4) months and 87% of hemodialysis sessions. Participants cycled for a median of 65 (interquartile range: 39-76) minutes per session, with frequent variability noted between participants and different hemodialysis sessions for the same participant. Nine patients completed the European Quality of Life Health Questionnaire prestudy, with 5 (56%) also completing it poststudy. Interviews with 9 patients, 4 nurses, and 1 physiotherapist led to the identification of themes instrumental to implementation: a supportive community dialysis unit, shared responsibility, knowledge of patients/providers, and benefits associated with engagement. Themes that were identified as being key to acceptability in this remote dialysis unit were trust, connection, and engagement through common values.

LIMITATIONS

Due to dialysis unit size, we had a small number of participants.

CONCLUSIONS

This study demonstrates the feasibility of implementing best practice in a remote community and provides insight into the elements of context and participation that contribute to acceptability in the implementation of intradialytic cycling.

Association between serum osteoprotegerin level and mortality in kidney transplant recipients - a prospective observational cohort study

Paradoxically, higher serum levels of osteoprotegerin (OPG: a vascular calcification inhibitor) have been associated with increased arterial stiffness, risk of cardiovascular disease and all-cause mortality. A few studies reported that post-transplant OPG levels are associated with mortality in kidney transplant (KT) recipients. In this study, this association was assessed in a cohort of prevalent KT recipients, adjusting for previously untested potential confounders, including fibroblast growth factor 23 (FGF23) and interleukin 6 (IL-6). Socio-demographic and clinical parameters, medical and transplant history, and laboratory data were collected from 982 prevalent KT recipients. The association between serum OPG and all-cause mortality over a 6-year follow-up period was examined using Kaplan-Meier survival curves and multivariable-adjusted Cox regression models. Participants with high serum OPG were more likely female, older, deceased donor KT recipients and have more comorbidity, lower eGFR, higher FGF23, higher IL-6, and longer dialysis vintage. Each 1 pmol/l higher serum OPG level was associated with a 49% higher risk of mortality (hazard ratio (HR) [95% confidence interval (CI)]: 1.49 [1.40-1.61]). This association persisted after adjusting for confounders (HR [95% CI]: 1.20 [1.10-1.30]). In conclusion, serum OPG was associated with all-cause mortality independent of several novel confounders in prevalent KT recipients.

Health claims databases used for kidney research around the world

Health claims databases offer opportunities for studies on large populations of patients with kidney disease and health outcomes in a non-experimental setting. Among others, their unique features enable studies on healthcare costs or on longitudinal, epidemiological data with nationwide coverage. However, health claims databases also have several limitations. Because clinical data and information on renal function are often lacking, the identification of patients with kidney disease depends on the actual presence of diagnosis codes only. Investigating the validity of these data is therefore crucial to assess whether outcomes derived from health claims data are truly meaningful. Also, one should take into account the coverage and content of a health claims database, especially when making international comparisons. In this article, an overview is provided of international health claims databases and their main publications in the area of nephrology. The structure and contents of the Dutch health claims database will be described, as well as an initiative to use the outcomes for research and the development of the Dutch Kidney Atlas. Finally, we will discuss to what extent one might be able to identify patients with kidney disease using health claims databases, as well as their strengths and limitations.

Developing and validating an algorithm to identify incident chronic dialysis patients using administrative data

BACKGROUND

Administrative healthcare databases are widespread and are often standardized with regard to their content and data coding, thus they can be used also as data sources for surveillance and epidemiological research. Chronic dialysis requires patients to frequently access hospital and clinic services, causing a heavy burden to healthcare providers. This also means that these patients are routinely tracked on administrative databases, yet very few case definitions for their identification are currently available. The aim of this study was to develop two algorithms derived from administrative data for identifying incident chronic dialysis patients and test their validity compared to the reference standard of the regional dialysis registry.

METHODS

The algorithms are based on data retrieved from hospital discharge records (HDR) and ambulatory specialty visits (ASV) to identify incident chronic dialysis patients in an Italian region. Subjects are included if they have at least one event in the HDR or ASV databases based on the ICD9-CM dialysis-related diagnosis or procedure codes in the study period. Exclusion criteria comprise non-residents, prevalent cases, or patients undergoing temporary dialysis, and are evaluated only on ASV data by the first algorithm, on both ASV and HDR data by the second algorithm. We validated the algorithms against the Emilia-Romagna regional dialysis registry by searching for incident patients in 2014 and performed sensitivity analyses by modifying the criteria to define temporary dialysis.

RESULTS

Algorithm 1 identified 680 patients and algorithm 2 identified 676 initiating dialysis in 2014, compared to 625 patients included in the regional dialysis registry. Sensitivity for the two algorithms was respectively 90.8 and 88.4%, positive predictive value 84.0 and 82.0%, and percentage agreement was 77.4 and 74.1%.

CONCLUSIONS

Algorithms relying on retrieval of administrative records have high sensitivity and positive predictive value for the identification of incident chronic dialysis patients. Algorithm 1, which showed the higher accuracy and has a simpler case definition, can be used in place of regional dialysis registries when they are not present or sufficiently developed in a region, or to improve the accuracy and timeliness of existing registries.

Effectiveness and Safety of Different Rivaroxaban Dosage Regimens in Patients with Non-Valvular Atrial Fibrillation: A Nationwide, Population-Based Cohort Study

The objective of this study is to evaluate the effectiveness of different rivaroxaban dosage regimens in preventing ischemic stroke and systemic thromboembolism among Asians. A retrospective cohort study was conducted on data from nationwide insurance claims in Taiwan. Patients with non-valvular atrial fibrillation under warfarin or rivaroxaban therapy were included. Propensity score matching was used to balance the covariates, and Cox-proportional hazard models were applied to compare the effectiveness and safety of each treatment group. Rivaroxaban was associated with a significantly lower risk of venous thromboembolism (hazard ratio [HR]: 0.51; 95% confidence interval [CI]: 0.29–0.92, P = 0.02) and intracranial hemorrhage (HR: 0.48; 95% CI: 0.32–0.72, P < 0.001) than warfarin. Rivaroxaban 20 mg and 15 mg were associated with a significantly lower risk of ischemic stroke (20 mg, HR: 0.48; CI: 0.29–0.80, P = 0.005; 15 mg, HR: 0.69; CI: 0.53–0.90, P = 0.005), but rivaroxaban 10 mg was not. In the subgroup analysis of patients older than 65 years, the results were generally the same, except that rivaroxaban had a significantly lower risk of ischemic stroke than warfarin.

Validation of the Kidney Failure Risk Equation in Manitoba

Background:

Patients with chronic kidney disease (CKD) are at risk to progress to kidney failure. We previously developed the Kidney Failure Risk Equation (KFRE) to predict progression to kidney failure in patients referred to nephrologists.

Objective:

The objective of this study was to determine the ability of the KFRE to discriminate which patients will progress to kidney failure in an unreferred population.

Design:

A retrospective cohort study was conducted using administrative databases.

Setting:

This study took place in Manitoba, Canada.

Measurements:

Age, sex, estimated glomerular filtration rate (eGFR), and urine albumin-to-creatinine ratio (ACR) were measured.

Methods:

We included patients from the Diagnostic Services of Manitoba database with an eGFR <60 mL/min/1.73 m² and ACR measured between October 2006 and March 2007. Five-year kidney failure risk was predicted using the 4-variable KFRE and compared with treated kidney failure events from the Manitoba Renal Program database. Sensitivity and specificity for KFRE risk thresholds (3% and 10% over 5 years) were compared with eGFR thresholds (30 and 45 mL/min/1.73 m²).

Results:

Of 1512 included patients, 151 developed kidney failure over the 5-year follow-up period. The 4-variable KFRE showed a superior prognostic discrimination compared with eGFR alone (area under the receiver operating characteristic curve [AUROC] values, 0.90 [95% confidence interval {CI}: 0.88-0.92] for KFRE vs 0.78 [95% CI: 0.74-0.83] for eGFR). At a 3% threshold over 5 years, the KFRE had a sensitivity of 97% and a specificity of 62%. At 10% risk, sensitivity was 86%, and specificity was 80%.

Limitations:

Only 11.7% of stage 3-5 CKD patients had simultaneous ACR measurement. The KFRE does not account for other indications for referral such as suspected glomerulonephritis, polycystic kidney disease, and recurrent stone disease.

Conclusions:

The KFRE has been validated in a population with a demographic and referral profile heretofore untested and performs well at predicting 5-year risk of kidney failure in a population-based sample of Manitobans with CKD stages 3 to 5. Thresholds of 3% and 10% over 5 years are sensitive, specific, and can be used in clinical decision making. Further testing of the 4-variable KFRE and these thresholds in clinical practice should be considered.

Screening for chronic kidney disease in Canadian indigenous peoples is cost-effective

Canadian indigenous (First Nations) have rates of kidney failure that are 2- to 4-fold higher than the non-indigenous general Canadian population. As such, a strategy of targeted screening and treatment for CKD may be cost-effective in this population. Our objective was to assess the cost utility of screening and subsequent treatment for CKD in rural Canadian indigenous adults by both estimated glomerular filtration rate and the urine albumin-to-creatinine ratio. A decision analytic Markov model was constructed comparing the screening and treatment strategy to usual care. Primary outcomes were presented as incremental cost-effectiveness ratios (ICERs) presented as a cost per quality-adjusted life-year (QALY). Screening for CKD was associated with an ICER of $23,700/QALY in comparison to usual care. Restricting the model to screening in communities accessed only by air travel (CKD prevalence 34.4%), this ratio fell to $7,790/QALY. In road accessible communities (CKD prevalence 17.6%) the ICER was $52,480/QALY. The model was robust to changes in influential variables when tested in univariate sensitivity analyses. Probabilistic sensitivity analysis found 72% of simulations to be cost-effective at a $50,000/QALY threshold and 93% of simulations to be cost-effective at a $100,000/QALY threshold. Thus, targeted screening and treatment for CKD using point-of-care testing equipment in rural Canadian indigenous populations is cost-effective, particularly in remote air access-only communities with the highest risk of CKD and kidney failure. Evaluation of targeted screening initiatives with cluster randomized controlled trials and integration of screening into routine clinical visits in communities with the highest risk is recommended.

The Prevalence of CKD in Rural Canadian Indigenous Peoples: Results From the First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis (FINISHED) Screen, Triage, and Treat Program

BACKGROUND

Indigenous Canadians have high rates of risk factors for chronic kidney disease (CKD), in particular diabetes. Furthermore, they have increased rates of complications associated with CKD, such as kidney failure and vascular disease. Our objective was to describe the prevalence of CKD in this population.

STUDY DESIGN

Cross-sectional cohort.

SETTING & PARTICIPANTS

Indigenous (First Nations) Canadians 18 years or older screened as part of the First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis (FINISHED) project, an initiative completed in 2015 that accomplished community-wide screening in 11 rural communities in Manitoba, Canada.

PREDICTORS

Indigenous ethnicity and geographic location (communities accessible by road compared with those accessible only by air).

OUTCOME

Prevalence of CKD, presumed based on a single ascertainment of urine albumin-creatinine ratio (UACR) ≥ 30mg/g and/or estimated glomerular filtration rate (eGFR)<60mL/min/1.73m(2).

MEASUREMENTS

Kidney function measured by eGFR (CKD-EPI creatinine equation) and UACR.

RESULTS

1,346 adults were screened; 25.5% had CKD, defined as UACR≥30mg/g or eGFR<60mL/min/1.73m(2). Communities accessible by road had a lower prevalence of CKD (17.6%) than more remote communities accessible only by air (34.4%). Of those screened, 3.3% had reduced kidney function (defined as eGFR<60mL/min/1.73m(2)). Severely increased albuminuria was present in 5.0% of those screened.

LIMITATIONS

Presumption of chronicity based on a single ascertainment. There is a possibility of sampling bias, the net direction of which is uncertain.

CONCLUSIONS

We found a 2-fold higher prevalence of CKD in indigenous Canadians in comparison to the general population and a prevalence of severely increased albuminuria that was 5-fold higher. This is comparable to patients with diabetes and/or hypertension. Public health strategies to screen, triage, and treat all Canadian indigenous peoples with CKD should be considered.

Functionalized MWCNTs in improving the performance and biocompatibility of potential hemodialysis membranes

Functionalized multi-walled carbon nanotube incorporated polyetherimide mixed matrix membranes for blood purification application.

Patient and caregiver values, beliefs and experiences when considering home dialysis as a treatment option: a semi-structured interview study

BACKGROUND

Home dialysis can offer improved quality of life and economic benefits compared with facility dialysis. Yet the uptake of home dialysis remains low around the world, which may be partly due to patients' lack of knowledge and barriers to shared and informed decision-making. We aimed to describe patient and caregiver values, beliefs and experiences when considering home dialysis, to inform strategies to align policy and practice with patients' needs.

METHODS

Semi-structured interviews with adult patients with chronic kidney disease Stage 4-5D (on dialysis <1 year) and their caregivers, recruited from three nephrology centres in New Zealand. Transcripts were analysed thematically.

RESULTS

In total, 43 patients [pre-dialysis (n = 18), peritoneal dialysis (n = 13), home haemodialysis (n = 4) and facility haemodialysis (n = 9)] and 9 caregivers participated. We identified five themes related to home dialysis: lacking decisional power (complexity of information, limited exposure to home dialysis, feeling disempowered, deprived of choice, pressure to choose), sustaining relationships (maintaining cultural involvement, family influence, trusting clinicians, minimizing social isolation), reducing lifestyle disruption (sustaining employment, avoiding relocation, considering additional expenses, seeking flexible schedules, creating free time), gaining confidence in choice (guarantee of safety, depending on professional certainty, reassurance from peers, overcoming fears) and maximizing survival.

CONCLUSIONS

To engage and empower patients and caregivers to consider home dialysis, a stronger emphasis on the development of patient-focused educational programmes and resources is suggested. Pre-dialysis and home dialysis programmes that address health literacy and focus on cultural and social values may reduce fears and build confidence around decisions to undertake home dialysis. Financial burdens may be minimized through provision of reimbursement programmes, employment support and additional assistance for patients, particularly those residing in remote areas.

Determination of the optimal case definition for the diagnosis of end-stage renal disease from administrative claims data in Manitoba, Canada

INTRODUCTION

End-stage renal disease (ESRD) is a major public health problem with increasing prevalence and costs. An understanding of the long-term trends in dialysis rates and outcomes can help inform health policy. We determined the optimal case definition for the diagnosis of ESRD using administrative claims data in the province of Manitoba over a 7-year period.

METHODS

We determined the sensitivity, specificity, predictive value and overall accuracy of 4 administrative case definitions for the diagnosis of ESRD requiring chronic dialysis over different time horizons from Jan. 1, 2004, to Mar. 31, 2011. The Manitoba Renal Program Database served as the gold standard for confirming dialysis status.

RESULTS

During the study period, 2562 patients were registered as recipients of chronic dialysis in the Manitoba Renal Program Database. Over a 1-year period (2010), the optimal case definition was any 2 claims for outpatient dialysis, and it was 74.6% sensitive (95% confidence interval [CI] 72.3%-76.9%) and 94.4% specific (95% CI 93.6%-95.2%) for the diagnosis of ESRD. In contrast, a case definition of at least 2 claims for dialysis treatment more than 90 days apart was 64.8% sensitive (95% CI 62.2%-67.3%) and 97.1% specific (95% CI 96.5%-97.7%). Extending the period to 5 years greatly improved sensitivity for all case definitions, with minimal change to specificity; for example, for the optimal case definition of any 2 claims for dialysis treatment, sensitivity increased to 86.0% (95% CI 84.7%-87.4%) at 5 years.

CONCLUSION

Accurate case definitions for the diagnosis of ESRD requiring dialysis can be derived from administrative claims data. The optimal definition required any 2 claims for outpatient dialysis. Extending the claims period to 5 years greatly improved sensitivity with minimal effects on specificity for all case definitions.

Mass screening for chronic kidney disease in rural and remote Canadian first nations people: methodology and demographic characteristics

Background

Screening the general population for Chronic Kidney Disease is not currently recommended.. Rural and remote Canadian First Nations people suffer a disproportionate burden of Kidney Failure. The First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis (FINISHED) project intends to test the hypothesis that a mobile, mass screening initiative available to all First Nations people 10 years of age and older residing in rural and/or remote communities, is feasible, will improve health outcomes and is cost effective.

Objectives

The objective of this manuscript is to describe the key elements required to design, implement and evaluate such a program and describe key characteristics of our screened cohort.

Design

Methods and cohort description.

Setting

11 First Nations communities within 2 Tribal Councils in Manitoba, Canada.

Patients

All First Nations individuals between the ages of 10–80 living in the 11communities were eligible for the screening initiative.

Measurements

Screening Rates achieved within communities.

Methods

An interdisciplinary team partnership was established between the Diabetes Integration Project and the Manitoba Renal Program. Stakeholder consultation was obtained and protocols developed to mass screen community members using point of care testing equipment. All people screened were risk stratified, counselled and referred to nephrologists as required in real time, based on risk.

Results

As of August 31, 2014, 1480 people in 11 communities over 2 Tribal Councils have been successfully screened. A mean screening rate of 21% of all community members eligible (aged 10–80) has been achieved. All patients at intermediate or high risk of kidney failure have been seen by nephrologists within 1 month of screening.

Limitations

Long term outcomes of kidney failure rates not assessed for at least 5 years. Alternative public health initiatives to reduce kidney failure not investigated.

Conclusions

Point of care mass screening, real time risk prediction and counselling of First Nations people at high risk of Kidney Failure is feasible in rural and remote communities. Further analysis of this cohort will describe theepidemiology of CKD in these communities, and test the cost effectiveness of this strategy.

Electronic supplementary material

The online version of this article (doi:10.1186/s40697-015-0046-9) contains supplementary material, which is available to authorized users.