National health policies and strategies for addressing chronic kidney disease: Data from the International Society of Nephrology Global Kidney Health Atlas

National strategies for addressing chronic kidney disease (CKD) are crucial to improving kidney health. We sought to describe country-level variations in non-communicable disease (NCD) strategies and CKD-specific policies across different regions and income levels worldwide. The International Society of Nephrology Global Kidney Health Atlas (GKHA) was a multinational cross-sectional survey conducted between July and October 2018. Responses from key opinion leaders in each country regarding national NCD strategies, the presence and scope of CKD-specific policies, and government recognition of CKD as a health priority were described overall and according to region and income level. 160 countries participated in the GKHA survey, comprising 97.8% of the world's population. Seventy-four (47%) countries had an established national NCD strategy, and 53 (34%) countries reported the existence of CKD-specific policies, with substantial variation across regions and income levels. Where CKD-specific policies existed, non-dialysis CKD care was variably addressed. 79 (51%) countries identified government recognition of CKD as a health priority. Low- and low-middle income countries were less likely to have strategies and policies for addressing CKD and have governments which recognise it as a health priority. The existence of CKD-specific policies, and a national NCD strategy more broadly, varied substantially across different regions around the world but was overall suboptimal, with major discrepancies between the burden of CKD in many countries and governmental recognition of CKD as a health priority. Greater recognition of CKD within national health policy is critical to improving kidney healthcare globally.

Trends in nephrology referral patterns for patients with chronic kidney disease: Retrospective cohort study

Introduction

Information on early, guideline discordant referrals in nephrology is limited. Our objective was to investigate trends in referral patterns to nephrology for patients with chronic kidney disease (CKD).

Methods

Retrospective cohort study of adults with ≥1 visits to a nephrologist from primary care with ≥1 serum creatinine and/or urine protein measurement <180 days before index nephrology visit, from 2006 and 2019 in Alberta, Canada. Guideline discordant referrals were those that did not meet ≥1 of: Estimated glomerular filtration rate (eGFR) ˂ 30 mL/min/1.73m², persistent albuminuria (ACR ≥ 300 mg/g, PCR ≥ 500 mg/g, or Udip ≥ 2+), or progressive and persistent decline in eGFR until index nephrology visit (≥ 5 mL/min/1.73m²).

Results

Of 69,372 patients with CKD, 28,518 (41%) were referred in a guideline concordant manner. The overall rate of first outpatient visits to nephrology increased from 2006 to 2019, although guideline discordant referrals showed a greater increase (trend 21.9 per million population/year, 95% confidence interval 4.3, 39.4) versus guideline concordant referrals (trend 12.4 per million population/year, 95% confidence interval 5.7, 19.0). The guideline concordant cohort were more likely to be on renin-angiotensin system blockers or beta blockers (hazard ratio 1.14, 95% confidence interval 1.12, 1.16), and had a higher risk of CKD progression (hazard ratio 1.09, 95% confidence interval 1.06, 1.13), kidney failure (hazard ratio 7.65, 95% confidence interval 6.83, 8.56), cardiovascular event (hazard ratio 1.40, 95% confidence interval 1.35,1.45) and mortality (hazard ratio 1.58, 95% confidence interval 1.52, 1.63).

Conclusions

A significant proportion nephrology referrals from primary care were not consistent with current guideline-recommended criteria for referral. Further work is needed to identify quality improvement initiatives aimed at enhancing referral patterns of patients with CKD.

Global Estimates of Capacity for Kidney Transplantation in World Countries and Regions

BACKGROUND

Kidney transplantation (KT) is the optimal treatment for kidney failure and is associated with better quality of life and survival relative to dialysis. However, knowledge of the current capacity of countries to deliver KT is limited. This study reports on findings from the 2018 International Society of Nephrology Global Kidney Health Atlas survey, specifically addressing the availability, accessibility, and quality of KT across countries and regions.

METHODS

Data were collected from published online sources, and a survey was administered online to key stakeholders. All country-level data were analyzed by International Society of Nephrology region and World Bank income classification.

RESULTS

Data were collected via a survey in 182 countries, of which 155 answered questions pertaining to KT. Of these, 74% stated that KT was available, with a median incidence of 14 per million population (range: 0.04-70) and median prevalence of 255 per million population (range: 3-693). Accessibility of KT varied widely; even within high-income countries, it was disproportionately lower for ethnic minorities. Universal health coverage of all KT treatment costs was available in 31%, and 57% had a KT registry.

CONCLUSIONS

There are substantial variations in KT incidence, prevalence, availability, accessibility, and quality worldwide, with the lowest rates evident in low- and lower-middle income countries. Understanding these disparities will inform efforts to increase awareness and the adoption of practices that will ensure high-quality KT care is provided around the world.

Availability, Accessibility, and Quality of Conservative Kidney Management Worldwide

BACKGROUND AND OBJECTIVES

People with kidney failure typically receive KRT in the form of dialysis or transplantation. However, studies have suggested that not all patients with kidney failure are best suited for KRT. Additionally, KRT is costly and not always accessible in resource-restricted settings. Conservative kidney management is an alternate kidney failure therapy that focuses on symptom management, psychologic health, spiritual care, and family and social support. Despite the importance of conservative kidney management in kidney failure care, several barriers exist that affect its uptake and quality.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Global Kidney Health Atlas is an ongoing initiative of the International Society of Nephrology that aims to monitor and evaluate the status of global kidney care worldwide. This study reports on findings from the 2018 Global Kidney Health Atlas survey, specifically addressing the availability, accessibility, and quality of conservative kidney management.

RESULTS

Respondents from 160 countries completed the survey, and 154 answered questions pertaining to conservative kidney management. Of these, 124 (81%) stated that conservative kidney management was available. Accessibility was low worldwide, particularly in low-income countries. Less than half of countries utilized multidisciplinary teams (46%); utilized shared decision making (32%); or provided psychologic, cultural, or spiritual support (36%). One-quarter provided relevant health care providers with training on conservative kidney management delivery.

CONCLUSIONS

Overall, conservative kidney management is available in most countries; however, it is not optimally accessible or of the highest quality.

Availability, coverage, and scope of health information systems for kidney care across world countries and regions

BACKGROUND

Health information systems (HIS) are fundamental tools for the surveillance of health services, estimation of disease burden and prioritization of health resources. Several gaps in the availability of HIS for kidney disease were highlighted by the first iteration of the Global Kidney Health Atlas.

METHODS

As part of its second iteration, the International Society of Nephrology conducted a cross-sectional global survey between July and October 2018 to explore the coverage and scope of HIS for kidney disease, with a focus on kidney replacement therapy (KRT).

RESULTS

Out of a total of 182 invited countries, 154 countries responded to questions on HIS (85% response rate). KRT registries were available in almost all high-income countries, but few low-income countries, while registries for non-dialysis chronic kidney disease (CKD) or acute kidney injury (AKI) were rare. Registries in high-income countries tended to be national, in contrast to registries in low-income countries, which often operated at local or regional levels. Although cause of end-stage kidney disease, modality of KRT and source of kidney transplant donors were frequently reported, few countries collected data on patient-reported outcome measures and only half of low-income countries recorded process-based measures. Almost no countries had programs to detect AKI and practices to identify CKD-targeted individuals with diabetes, hypertension and cardiovascular disease, rather than members of high-risk ethnic groups.

CONCLUSIONS

These findings confirm significant heterogeneity in the global availability of HIS for kidney disease and highlight important gaps in their coverage and scope, especially in low-income countries and across the domains of AKI, non-dialysis CKD, patient-reported outcomes, process-based measures and quality indicators for KRT service delivery.

Hemodialysis Use and Practice Patterns: An International Survey Study

RATIONALE & OBJECTIVE

Hemodialysis (HD) is the most common form of kidney replacement therapy. This study aimed to examine the use, availability, accessibility, affordability, and quality of HD care worldwide.

STUDY DESIGN

A cross-sectional survey.

SETTING & PARTICIPANTS

Stakeholders (clinicians, policy makers, and consumer representatives) in 182 countries were convened by the International Society of Nephrology from July to September 2018.

OUTCOMES

Use, availability, accessibility, affordability, and quality of HD care.

ANALYTICAL APPROACH

Descriptive statistics.

RESULTS

Overall, representatives from 160 (88%) countries participated. Median country-specific use of maintenance HD was 298.4 (IQR, 80.5-599.4) per million population (pmp). Global median HD use among incident patients with kidney failure was 98.0 (IQR, 81.5-140.8) pmp and median number of HD centers was 4.5 (IQR, 1.2-9.9) pmp. Adequate HD services (3-4 hours 3 times weekly) were generally available in 27% of low-income countries. Home HD was generally available in 36% of high-income countries. 32% of countries performed monitoring of patient-reported outcomes; 61%, monitoring of small-solute clearance; 60%, monitoring of bone mineral markers; 51%, monitoring of technique survival; and 60%, monitoring of patient survival. At initiation of maintenance dialysis, only 5% of countries used an arteriovenous access in almost all patients. Vascular access education was suboptimal, funding for vascular access procedures was not uniform, and copayments were greater in countries with lower levels of income. Patients in 23% of the low-income countries had to pay >75% of HD costs compared with patients in only 4% of high-income countries.

LIMITATIONS

A cross-sectional survey with possibility of response bias, social desirability bias, and limited data collection preventing in-depth analysis.

CONCLUSIONS

In summary, findings reveal substantial variations in global HD use, availability, accessibility, quality, and affordability worldwide, with the lowest use evident in low- and lower-middle-income countries.

Peritoneal Dialysis Use and Practice Patterns: An International Survey Study

RATIONALE & OBJECTIVE

Approximately 11% of people with kidney failure worldwide are treated with peritoneal dialysis (PD). This study examined PD use and practice patterns across the globe.

STUDY DESIGN

A cross-sectional survey.

SETTING & PARTICIPANTS

Stakeholders including clinicians, policy makers, and patient representatives in 182 countries convened by the International Society of Nephrology between July and September 2018.

OUTCOMES

PD use, availability, accessibility, affordability, delivery, and reporting of quality outcome measures.

ANALYTICAL APPROACH

Descriptive statistics.

RESULTS

Responses were received from 88% (n=160) of countries and there were 313 participants (257 nephrologists [82%], 22 non-nephrologist physicians [7%], 6 other health professionals [2%], 17 administrators/policy makers/civil servants [5%], and 11 others [4%]). 85% (n=156) of countries responded to questions about PD. Median PD use was 38.1 per million population. PD was not available in 30 of the 156 (19%) countries responding to PD-related questions, particularly in countries in Africa (20/41) and low-income countries (15/22). In 69% of countries, PD was the initial dialysis modality for≤10% of patients with newly diagnosed kidney failure. Patients receiving PD were expected to pay 1% to 25% of treatment costs, and higher (>75%) copayments (out-of-pocket expenses incurred by patients) were more common in South Asia and low-income countries. Average exchange volumes were adequate (defined as 3-4 exchanges per day or the equivalent for automated PD) in 72% of countries. PD quality outcome monitoring and reporting were variable. Most countries did not measure patient-reported PD outcomes.

LIMITATIONS

Low responses from policy makers; limited ability to provide more in-depth explanations underpinning outcomes from each country due to lack of granular data; lack of objective data.

CONCLUSIONS

Large inter- and intraregional disparities exist in PD availability, accessibility, affordability, delivery, and reporting of quality outcome measures around the world, with the greatest gaps observed in Africa and South Asia.

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder

Purpose of review:

(1) To provide commentary on the 2017 update to the Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD); (2) to apply the evidence-based guideline update for implementation within the Canadian health care system; (3) to provide comment on the care of children with chronic kidney disease (CKD); and (4) to identify research priorities for Canadian patients.

Sources of information:

The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD.

Methods:

The commentary committee co-chairs selected potential members based on their knowledge of the Canadian kidney community, aiming for wide representation from relevant disciplines, academic and community centers, and different geographical regions.

Key findings:

We agreed with many of the recommendations in the clinical practice guideline on the diagnosis, evaluation, prevention, and treatment of CKD-MBD. However, based on the uncommon occurrence of abnormalities in calcium and phosphate and the low likelihood of severe abnormalities in parathyroid hormone (PTH), we recommend against screening and monitoring levels of calcium, phosphate, PTH, and alkaline phosphatase in adults with CKD G3. We suggest and recommend monitoring these parameters in adults with CKD G4 and G5, respectively. In children, we agree that monitoring for CKD-MBD should begin in CKD G2, but we suggest measuring ionized calcium, rather than total calcium or calcium adjusted for albumin. With regard to vitamin D, we suggest against routine screening for vitamin D deficiency in adults with CKD G3-G5 and G1T-G5T and suggest following population health recommendations for adequate vitamin D intake. We recommend that the measurement and management of bone mineral density (BMD) be according to general population guidelines in CKD G3 and G3T, but we suggest against routine BMD testing in CKD G4-G5, CKD G4T-5T, and in children with CKD. Based on insufficient data, we also recommend against routine bone biopsy in clinical practice for adults with CKD or CKD-T, or in children with CKD, although we consider it an important research tool.

Limitations:

The committee relied on the evidence summaries produced by KDIGO. The CSN committee did not replicate or update the systematic reviews.

Patients on Chronic Peritoneal Dialysis for Ten Years or More in North America

Thirty-six patients on peritoneal dialysis (PD) for more than ten years in six North American centers were analyzed retrospectively. In the six centers, the percentage of patients surviving for more than ten years varied between 0.8% and 7.3%. The study group included 27 females and 9 males aged 38.6 ± 14.2 years [mean ± standard deviation (SD)] at the start of treatment. Of the 36 patients, 28 were Caucasian.

The most common cause of end-stage renal disease (ESRD), present in 12 patients, was chronic glomerulonephritis. Only 4 patients had diabetes. At the beginning of the study, 19 patients had hypertension (the most common comorbid condition); 11 had no comorbid conditions at the start.

Creatinine clearance at the start was 4.12 ± 3.5 mL per minute, and the mean duration to anuria was 51 ± 25 months. Mean initial body weight was 55 ± 9 kg, and mean body surface area was 1.5 ± 0.2 m2. Serum albumin levels showed an increase from 33.8 ± 3.6 g/L at the start of the study to 38.2 ± 3.9 g/L at the end.

Hospitalization rate was low at 0.5 ± 0.3 admissions per patient–year, and duration of hospitalization was 4.8 ± 3.7 days per patient–year. Peritonitis was the most common cause of hospitalization. The mean peritonitis rate was 1 episode every 52 ± 48 patient–months.

There were 36 catheter changes in 18 patients; 16 patients had a single PD catheter throughout the period of study. Autonomous hyperparathyroidism was the most common long-term complication.

At the end of the study period, 11 patients were still on PD, 9 had died, 5 had been transferred to hemodialysis (HD), 1 was alive with a functioning allograft, and 1 was lost to follow-up.

We conclude that patients who survive longer than ten years on PD are most likely to be young Caucasian females, small in body size, who are non diabetic, with few comorbid conditions. These long-term survivors have few hospitalizations, and their peritonitis rate is low. In this group of patients, severe autonomous hyperparathyroidism is the most common long-term complication.

Excellent Technique Survival on Home Peritoneal Dialysis: Results of a Regional Program

Objective

To examine peritoneal dialysis technique survival in our regional, continuous ambulatory peritoneal dialysis (CAPD) program.

Design

Retrospective analysis.

Setting

Tertiary care dialysis programatan academic medical center.

Patients

155 patients representing all those in the peritoneal dialysis program between October 1, 1987 and October 1,1990.

Outcome measures

The study analyzed patient and technique survival as well as the reasons for discontinuation of dialysis. In addition, the incidence and type of peritonitis and exit-site infection were also analyzed.

Results

Three-year actuarial patient survival was 66% and three-year technique survival was 86%, with data censored for death and transplant patients. Fiftyseven percent of transfers to hemodialysis were due to peritonitis, usually fungal or multiorganism bacterial. Only 1 patient failed due to exit-site and tunnel infection, and 1 due to inadequate dialysis. The catheter removal rate was 0.04 per patient-year.

Conclusions

Excellent CAPD technique survival can be achieved if exit-site and tunnel infection rates are low.

Status of care for end stage kidney disease in countries and regions worldwide: international cross sectional survey

OBJECTIVE

To determine the global capacity (availability, accessibility, quality, and affordability) to deliver kidney replacement therapy (dialysis and transplantation) and conservative kidney management.

DESIGN

International cross sectional survey.

SETTING

International Society of Nephrology (ISN) survey of 182 countries from July to September 2018.

PARTICIPANTS

Key stakeholders identified by ISN's national and regional leaders.

MAIN OUTCOME MEASURES

Markers of national capacity to deliver core components of kidney replacement therapy and conservative kidney management.

RESULTS

Responses were received from 160 (87.9%) of 182 countries, comprising 97.8% (7338.5 million of 7501.3 million) of the world's population. A wide variation was found in capacity and structures for kidney replacement therapy and conservative kidney management-namely, funding mechanisms, health workforce, service delivery, and available technologies. Information on the prevalence of treated end stage kidney disease was available in 91 (42%) of 218 countries worldwide. Estimates varied more than 800-fold from 4 to 3392 per million population. Rwanda was the only low income country to report data on the prevalence of treated disease; 5 (<10%) of 53 African countries reported these data. Of 159 countries, 102 (64%) provided public funding for kidney replacement therapy. Sixty eight (43%) of 159 countries charged no fees at the point of care delivery and 34 (21%) made some charge. Haemodialysis was reported as available in 156 (100%) of 156 countries, peritoneal dialysis in 119 (76%) of 156 countries, and kidney transplantation in 114 (74%) of 155 countries. Dialysis and kidney transplantation were available to more than 50% of patients in only 108 (70%) and 45 (29%) of 154 countries that offered these services, respectively. Conservative kidney management was available in 124 (81%) of 154 countries. Worldwide, the median number of nephrologists was 9.96 per million population, which varied with income level.

CONCLUSIONS

These comprehensive data show the capacity of countries (including low income countries) to provide optimal care for patients with end stage kidney disease. They demonstrate substantial variability in the burden of such disease and capacity for kidney replacement therapy and conservative kidney management, which have implications for policy.

Ferric pyrophosphate citrate (Triferic™) administration via the dialysate maintains hemoglobin and iron balance in chronic hemodialysis patients

Background

Administration of ferric pyrophosphate citrate (FPC, Triferic™) via hemodialysate may allow replacement of ongoing uremic and hemodialysis-related iron losses. FPC donates iron directly to transferrin, bypassing the reticuloendothelial system and avoiding iron sequestration.

Methods

Two identical Phase 3, randomized, placebo-controlled trials (CRUISE 1 and 2) were conducted in 599 iron-replete chronic hemodialysis patients. Patients were dialyzed with dialysate containing 2 µM FPC-iron or standard dialysate (placebo) for up to 48 weeks. Oral or intravenous iron supplementation was prohibited, and doses of erythropoiesis-stimulating agents were held constant. The primary efficacy end point was the change in hemoglobin (Hgb) concentration from baseline to end of treatment (EoT). Secondary end points included reticulocyte hemoglobin content (CHr) and serum ferritin.

Results

In both trials, Hgb concentration was maintained from baseline to EoT in the FPC group but decreased by 0.4 g/dL in the placebo group (P < 0.001, combined results; 95% confidence interval [CI] 0.2–0.6). Placebo treatment resulted in significantly larger mean decreases from baseline in CHr (−0.9 pg versus −0.4 pg, P < 0.001) and serum ferritin (−133.1 µg/L versus −69.7 µg/L, P < 0.001) than FPC treatment. The proportions of patients with adverse and serious adverse events were similar in both treatment groups.

Conclusions

FPC delivered via dialysate during hemodialysis replaces iron losses, maintains Hgb concentrations, does not increase iron stores and exhibits a safety profile similar to placebo. FPC administered by hemodialysis via dialysate represents a paradigm shift in delivering maintenance iron therapy to hemodialysis patients.

Patient-level evaluation of community-based, multifactorial intervention to prevent diabetic nephropathy in northern alberta, Canada

OBJECTIVE

To examine whether patients with type 2 diabetes enrolled in community-based clinics uniformly benefit from interventions designed to achieve multiple risk factor targets.

METHODS

Using data from community-based clinics in Alberta, Canada, we examined whether patients achieved targets for blood pressure (<130/80 mm Hg), A1c (≤7%), low-density lipoprotein (LDL) cholesterol (<2.5 mmol/L), weight reduction, exercising, smoking cessation, and meal plan management among 235 patients between 2004 to 2007 with a 1-year follow-up. The effectiveness of the clinics was assessed by the number of targets achieved by individual patients. Patients achieving different degrees of success (0-2, 3-4, and ≥5 targets) were compared.

RESULTS

Mean age of patients at baseline was 62 years (standard deviation [SD], 12 years), 43% were female, 77% had a history of cardiovascular disease, and mean diabetes duration was 9 years (SD, 9 years). Overall, 47 patients achieved 0 to 2 targets (group 1), 132 achieved 3 to 4 targets (group 2), and 56 achieved ≥5 targets (group 3) out of 7 targets. More patients in group 1 were male and had longer diabetes duration and were more likely to smoke or use insulin. Despite reductions in A1c in all groups and similar use of antihypertensives, there was no improvement in weight or systolic blood pressure (which actually increased) in group 1. Successful patients (group 3) were more likely to report adherence with exercise and a meal plan.

CONCLUSIONS

Despite equally intensive, target-driven pharmacotherapy, this community-based multifactorial intervention was less effective among a subset of patients who did not adhere to lifestyle changes. Strategies to effectively address lifestyle factors will be important as this intervention is refined.

Low-intensity adjusted-dose warfarin for the prevention of hemodialysis catheter failure: a randomized, controlled trial

BACKGROUND AND OBJECTIVES

To determine whether warfarin prolongs the time to first mechanical-catheter failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a multicenter parallel-group randomized controlled trial with blinding of participants, trial staff, clinical staff, outcome assessors, and data analysts. Randomization was in a 1:1 ratio in blocks of four and was concealed by use of fax to a central pharmacy. Hemodialysis patients with newly-placed catheters received low-intensity monitored-dose warfarin, target international normalized ratio (INR) 1.5 to 1.9, or placebo, adjusted according to schedule of sham INR results. The primary outcome was time to first mechanical-catheter failure (inability to establish a circuit or blood flow less than 200 ml/min).

RESULTS

We randomized 174 patients: 87 to warfarin and 87 to placebo. Warfarin was associated with a hazard ratio (HR) of 0.90 (P=0.60; 95% confidence interval [CI], 0.57, 1.38) for time to first mechanical-catheter failure. Secondary analyses were: time to first guidewire exchange or catheter removal for mechanical failure (HR 0.78; 95% CI, 0.37, 1.6); time to catheter removal for mechanical failure (HR 0.67; 95% CI, 0.19, 2.37); and time to catheter removal for any cause (HR 0.89; 95% CI, 0.42, 1.81). Major bleeding occurred in 10 participants assigned to warfarin and seven on placebo (relative risk, 1.43; 95% CI, 0.57, 3.58; P=0.61).

CONCLUSIONS

We found no evidence for efficacy of low-intensity, monitored-dose warfarin in preventing mechanical-catheter failure.

Best threshold for diagnosis of stenosis or thrombosis within six months of access flow measurement in arteriovenous fistulae

Canadian clinical practice guidelines recommend performing angiography when access blood flow (Qa) is <500 ml/min in native vessel arteriovenous fistulae (AVF), but data on the value of Qa that best predicts stenosis are sparse. Because correction of stenosis in AVF improves patency rates, this issue seems worthy of investigation. Receiver-operating characteristic curves were constructed to examine the relationship between different threshold values of Qa and stenosis in 340 patients with AVF. Stenosis was defined by the composite outcome of access failure or angiographic stenosis occurring within 6 mo of the first Qa measurement. The Qa value was then classified as true negative, true positive, false negative, or false positive for stenosis. An additional analysis was performed in which Qa was corrected for systolic BP before assigning it to one of the four diagnostic categories. The area under the curve for the composite definition of stenosis was 0.86. Graphically, Qa thresholds of <500 and <600 ml/min had similar efficacy for detecting stenosis or access failure within 6 mo, and both seemed superior to <400 ml/min. However, the frequency of the composite definition of stenosis among AVF with Qa between 500 and 600 ml/min was only 6 (25%) of 24, as compared with 58 (76%) of 76 when Qa was <500 ml/min. This suggests that most lesions that would be found using a threshold of <600 ml/min occurred in AVF with Qa <500 ml/min and that the small gain in sensitivity associated with the <600-ml/min threshold would be outweighed by the reduced specificity compared with <500 ml/min. Correcting Qa for BP did not improve diagnostic performance or change these results, which were consistent in several sensitivity analyses. Qa measurements seemed to predict stenosis or incipient access failure equally well in groups defined by diabetic status, gender, and AVF location. In conclusion, it was found that Qa <500 ml/min seems to be the most appropriate threshold for performing angiography in patients with native vessel AVF. It is recommended that clinicians arrange angiography when Qa is <500 ml/min in AVF.

Extended Reuse of Polysulfone Hemodialysis Membranes Using Citric Acid and Heat

The concomitant use of citric acid and prolonged exposure to heat (CAH) is an increasingly common alternative to purely chemical means of reusing dialyzers. However, there are no data on the effects of reprocessing dialyzers with CAH beyond 15 uses. Increasing the number of reuses with CAH cannot be systematically undertaken unless its safety is documented. We hypothesized that discarding polysulfone dialyzers after the 25th rather than the 15th use would result in increased clearance of beta2-microglobulin (beta2MG) without clinically significant changes in small solute clearance or albumin loss. We studied 15 Fresenius F80B polysulfone dialyzers in five chronic hemodialysis patients. Dialyzers were reprocessed using 1.5% citric acid solution heated to 95 degrees C. Representative fractional collection and 10 minute timed collections of dialysate were performed at baseline and during uses 5, 10, 15, 20, and 25 for each dialyzer. Dialysate-side urea, creatinine, and beta2MG clearances were calculated, and total albumin was measured in dialysate. We used a mixed model to adjust for repeated measures (both within a given dialyzer and for the multiple dialyzers per patient). Of the 15 dialyzers studied, 3 (20%) failed before the 25th use. There was no significant change in urea or creatinine clearance with additional reuse (overall p values 0.20 and 0.60, respectively). A sustained increase in beta2MG clearance was observed after the fifth treatment compared with the first use (p < 0.001). Fractional collection showed that dialysate albumin loss increased significantly with additional reuses (p < 0.001) but did not increase significantly above baseline until treatment 25. Reprocessing of polysulfone dialyzers with CAH 25 times significantly increased albumin loss and beta2MG clearance but did not appear to affect urea or creatinine clearance. Increasing the maximum number of uses to 20 may permit cost savings compared with current practice without additional risk.

The cost-effectiveness of maintaining higher hemoglobin targets with erythropoietin in hemodialysis patients

BACKGROUND

There is uncertainty regarding the appropriate target hemoglobin level in hemodialysis patients treated with erythropoietin (EPO).

METHODS

We sought to determine the incremental cost-effectiveness of prescribing EPO to maintain different target hemoglobin levels, by incorporating the impact of EPO on health-related quality-of-life (HRQOL) issues and adopting the perspective of the health care purchaser. We evaluated the prescription of EPO to maintain target hemoglobin levels of 11.0 to 12.0, 12.0 to 12.5, and 14.0 g/dL, compared with 9.5 to 10.5 g/dL. Model outputs were quality-adjusted life expectancy and costs.

RESULTS

The base case analysis estimated intravenous EPO requirements to be 3523, 5078, 6097, and 9341 units three times per week to maintain targets of 9.5 to 10.5, 11.0 to 12.0, 12.0 to 12.5, and 14.0 g/dL, respectively. The cost per quality-adjusted life year (QALY) gained for the 11.0 to 12.0 g/dL target vs. 9.5 to 10.5 g/dL was $55,295 US. For the 12.0 to 12.5 g/dL target compared to 11.0 to 12.0 g/dL, and 14.0 g/dL target compared to 12.0 to 12.5 g/dL, the costs per QALY gained were $613,015 US and $828,215 US, respectively. In sensitivity analysis, clinically implausible reductions in hospitalization or EPO requirements associated with the two higher hemoglobin targets were required to make their incremental cost per QALY gained <$100,000 US.

CONCLUSION

Dosing intravenous EPO to achieve hemoglobin targets of 11.0 to 12.0 g/dL appears to be associated with incremental cost per QALY gained of $50,000 to $60,000, compared with a hemoglobin target of 9.5 to 10.5 g/dL. Aiming for hemoglobin targets in excess of 12.0 g/dL is associated with unfavorable cost-effectiveness ratios and should not be undertaken based on current data.

Quality of prereferral care in patients with chronic renal insufficiency

BACKGROUND

Appropriate care in chronic renal insufficiency (CRI) includes blood pressure and diabetes control, as well as the investigation and management of anemia, acidosis, and bone disease. There is a lack of data on the control of these parameters at the time of referral to a nephrologist. Similarly, early referral has been emphasized in the literature, yet very little published has examined current referral patterns.

METHODS

A single-center retrospective/prospective review of all new outpatient referrals to nephrologists in Halifax, Canada, in 1998 and 1999 was conducted to identify patients with CRI (serum creatinine > 1.6 mg/dL [141 micromol/L] for men or >1.2 mg/dL [106 micromol/L] for women). Quality of prereferral care was based on data from the initial clinic visit.

RESULTS

Of 1,050 charts reviewed, 411 patients met the study criteria. Twenty-six percent of patients had diabetes mellitus, 18% were referred with a calculated glomerular filtration rate less than 15 mL/min, and blood pressure was optimally controlled (<130 mm Hg systolic and <80 mm Hg diastolic) in only 24%. Only 44% of patients were administered an angiotensin-converting enzyme inhibitor. Patients were administered an average of 1.9 antihypertensive agents. Significant anemia (hemoglobin < 10 g/dL) was present in 21%, and appropriate investigations were performed in only 35% of these patients. Calcium levels less than 8.6 mg/dL (2.15 mmol/L) were found in 19% of patients, and only 14% of these patients were started on calcium supplement therapy. Phosphate levels greater than 5.0 mg/dL (1.6 mmol/L) were seen in 20% of patients, and 14% of these patients were on phosphate-binder therapy. Parathyroid hormone levels were more than five times normal values in 18% of patients, and 25% of patients had bicarbonate levels less than 23 mmol/L.

CONCLUSIONS

A significant proportion of patients referred with CRI receive inadequate prereferral care. Continuing education programs and referral guidelines must not only emphasize the importance of early referral, but also address the related consequences of CRI to delay the progression of renal disease and avoid complications.

A simple method to estimate the required dialysis time for cases of alcohol poisoning

BACKGROUND

Conventional dialysis management of ethylene glycol and methanol poisoning includes frequent intradialytic determinations of serum toxin concentration. Dialysis is continued until a target toxin concentration is reached. Initially, the required dialysis duration is unknown, making planning difficult. We devised a simple method to estimate the duration of dialysis required and avoid quantitation of multiple toxin samples.

METHODS

Using the assumption that toxic alcohols would have a dialysis clearance similar to urea, we proposed that required dialysis time (hours) to reach a 5 mmol/L toxin concentration target would be: [-V ln(5/A)]/0.06k, where V (liters) is the Watson estimate of total body water, A is the initial toxin concentration (mmol/L), and k is 80% of the manufacturer-specified dialyzer urea clearance (mL/min) at the initial observed blood flow rate. Directly measured dialysis and renal toxin clearance, and true dialysis requirement by conventional treatment protocol were compared with our estimate in two methanol and three ethylene glycol poisonings treated with Fresenius F8 dialyzers.

RESULTS

There were no clinically or statistically significant differences between predicted dialysis duration (7.6 +/- 1.9 hours, +/-SD) and that actually provided using hourly toxin concentration sampling (7.4 +/- 1.9 hours). Renal toxin clearance was negligible compared to that of dialysis, and predicted dialysis clearance did not differ significantly from that observed.

CONCLUSIONS

The simple estimate method is sufficiently valid to guide the prescription of dialysis for toxic alcohol poisoning. Data required at dialysis start include only the initial toxin concentration, dialyzer manufacturer's specified urea clearance at initial observed blood pump speed, and patient demographics to estimate total body water. This approach allows for planned dialysis therapy, without the need for additional toxin concentration measurements until dialysis is completed.

Progressive Increases in Peritoneal Dialysis Prescription: Patient Acceptance and Complication Rates

Peritoneal dialysis adequacy has an impact on patient mortality. Both the CANUSA study and DOQI Guidelines outline targets for adequacy, and it has been suggested that quantitative adequacy determinations be made at regular intervals. Some groups believe these targets are not achievable because of lack of patient acceptance and high complication rate. We examined the outcome of peritoneal dialysis in a setting where prescription changes are made on clinical grounds, and determined the complication rates and patient acceptance of prescription changes. A total of 154 patients commencing peritoneal dialysis from January 1, 1994,-December 31, 1996, were studied to determine reasons for dialysis prescription changes, patient acceptance of, and complications related to these changes. Point prevalence data for dialysis prescription for our center and other Canadian centers were obtained from the Canadian Institute for Health Information. Co-morbidity - adjusted patient and technique survival for our center versus other centers in Canada was performed by Poisson regression analysis. Dialysis prescription changes were based on clinical assessment. A total of 102 patients started on either > 8 L of dialysate or had an increase in dialysis prescription during the study period. These patients were heavier, on peritoneal dialysis for longer, and fewer were transplanted compared with the patients on standard prescription (8 L or less). Only 4% of patients refused the change in dialysis prescription, and only 13 peritoneal leaks occurred, resulting in 3 transfers to hemodialysis. Our center prescribed a larger number of exchanges than other Canadian centers in 1995-1997. Adjusted mortality rate ratios for our center versus the other Canadian Centers (1990-1996) are equal. The 3 year technique survival for peritoneal dialysis patients from our center between 1990-1996 was 75% vs. 61% for other centers in Canada. At last follow-up, > 60% of patients had a Kt/V urea >2.1 and 45% had a creatinine clearance > 70 L/1.73 m2/week. This Regional Program has successfully prescribed high volume and frequency peritoneal dialysis on clinical grounds alone. This practice is associated with high patient acceptance, equivalent mortality, and higher technique survival compared with the rest of Canada.

Patients on chronic peritoneal dialysis for ten years or more in North America

Thirty-six patients on peritoneal dialysis (PD) for more than ten years in six North American centers were analyzed retrospectively. In the six centers, the percentage of patients surviving for more than ten years varied between 0.8% and 7.3%. The study group included 27 females and 9 males aged 38.6 +/- 14.2 years [mean +/- standard deviation (SD)] at the start of treatment. Of the 36 patients, 28 were Caucasian. The most common cause of end-stage renal disease (ESRD), present in 12 patients, was chronic glomerulonephritis. Only 4 patients had diabetes. At the beginning of the study, 19 patients had hypertension (the most common comorbid condition); 11 had no comorbid conditions at the start. Creatinine clearance at the start was 4.12 +/- 3.5 mL per minute, and the mean duration to anuria was 51 +/- 25 months. Mean initial body weight was 55 +/- 9 kg, and mean body surface area was 1.5 +/- 0.2 m2. Serum albumin levels showed an increase from 33.8 +/- 3.6 g/L at the start of the study to 38.2 +/- 3.9 g/L at the end. Hospitalization rate was low at 0.5 +/- 0.3 admissions per patient-year, and duration of hospitalization was 4.8 +/- 3.7 days per patient-year. Peritonitis was the most common cause of hospitalization. The mean peritonitis rate was 1 episode every 52 +/- 48 patient-months. There were 36 catheter changes in 18 patients; 16 patients had a single PD catheter throughout the period of study. Autonomous hyperparathyroidism was the most common long-term complication. At the end of the study period, 11 patients were still on PD, 9 had died, 5 had been transferred to hemodialysis (HD), 1 was alive with a functioning allograft, and 1 was lost to follow-up. We conclude that patients who survive longer than ten years on PD are most likely to be young Caucasian females, small in body size, who are non diabetic, with few comorbid conditions. These long-term survivors have few hospitalizations, and their peritonitis rate is low. In this group of patients, severe autonomous hyperparathyroidism is the most common long-term complication.

Comparative hospitalization of hemodialysis and peritoneal dialysis patients in Canada

BACKGROUND

Most comparisons of hemodialysis (HD) and peritoneal dialysis (PD) have used mortality as an outcome. Relatively few studies have directly compared the hospitalization rates, an outcome of perhaps equal importance, of patients using these different dialysis modalities.

METHODS

Eight hundred twenty-two consecutive patients at 11 Canadian institutions with irreversible renal failure had an extensive assessment of comorbid illness and initial mode of dialysis collected prospectively immediately prior to starting dialysis therapy. The cohort was assembled between March 1993 and November 1994. The mean follow-up was 24 months. Admission data were used to compare hospitalization rates in HD and PD.

RESULTS

Thirty-four percent of patients at baseline and 50% at three months used PD. Twenty-five percent of HD and 32% of PD patients switched dialysis modality at least once after their first treatment (P = NS). Nine percent of HD patients and 30% of PD patients switched modality after three months (P < 0. 001). Total comorbidity was higher in HD patients at baseline (P < 0. 001) and at three months (P = 0.001). The overall hospitalization rate was 40.2 days per 1000 patient days after baseline and 38.0 days per 1000 patient days after three months. When an adjustment was made for baseline comorbid conditions, patients on PD had a lower rate of hospitalization in intention-to-treat analysis according to the type of dialysis in use at baseline (RR 0.85, 95% CI, 0.82 to 0.87, P < 0.001), but a higher rate according to the type of dialysis in use three months after study entry (RR 1.31, 95% CI, 1.27 to 1.34, P < 0.001). In analyses based on the amount of time actually spent on each treatment modality, PD was associated with a higher rate of hospitalization when analyzed according to the type of dialysis in use at baseline (RR 1.10, 95% CI, 1.07 to 1.13, P < 0.001) and according to the type of dialysis in use three months after study entry (RR 1.26, 95% CI, 1.23 to 1.30, P < 0.001).

CONCLUSIONS

Conclusions regarding comparative hospitalization rates are heavily dependent on the analytic starting point and on whether intention-to-treat or treatment-received analyses are used. When early treatment switches are accounted for, HD is associated with a lower rate of hospitalization than PD, but the effect is modest.

Peritoneal dialysis reduces the use of non native fistula access in dialysis programs

Access problems remain the major difficulty associated with chronic hemodialysis. Despite recent recommendations by the Dialysis Outcomes Quality Initiative (DOQI) that native arteriovenous (AV) fistulae are the optimal form of vascular access, grafts and central catheters are used by many patients. We analyzed our large Canadian regional dialysis program, which has a high prevalence of peritoneal dialysis, to examine the effect of dialysis modality choice on vascular access utilization. Point prevalence data were collected from our program in October 1997, and technique and patient survival data for the period 1990-1996 were analyzed and compared to data for the remainder of Canada from the Canadian Organ Replacement Register. Mortality rate ratios were estimated using a Poisson regression model to correct for comorbidity, age, and end-stage renal disease etiology. Of 141 in-center hemodialysis patients, 91 had an AV fistula, 1 had a polytetrafluoroethylene (PTFE) graft, and 49 were catheter-dependent. The program also included 20 home hemodialysis patients with AV fistulae, and 156 patients on peritoneal dialysis. No mortality risk differences between hemodialysis and peritoneal dialysis are seen in our center, nor are they seen for each modality in comparison with the remainder of Canada. Technique survival for peritoneal dialysis at our center was about 80% at 2 years, significantly greater than for Canada. For the program as a whole, 49% of patients used peritoneal dialysis 35% a native AV fistula, and 15% a central catheter. For Canada and the U.S.A. respectively, the comparable data were: peritoneal dialysis, 32% and 17%; native fistula, 33% and 15%; PTFE, 19% and 41%; and central catheter 16% and 27%. These data suggest that the use of peritoneal dialysis may allow reduced use of non native AV fistula access without mortality penalty.

Comparative mortality of hemodialysis and peritoneal dialysis in Canada

BACKGROUND

Comparisons of mortality rates in patients on hemodialysis versus those on peritoneal dialysis have been inconsistent. We hypothesized that comorbidity has an important effect on differential survival in these two groups of patients.

METHODS

Eight hundred twenty-two consecutive patients at 11 Canadian institutions with irreversible renal failure had an extensive assessment of comorbid illness collected prospectively, immediately prior to starting dialysis therapy. The cohort was assembled between March 1993 and November 1994; vital status was ascertained as of January 1, 1998.

RESULTS

The mean follow-up was 24 months. Thirty-four percent of patients at baseline, 50% at three months, and 51% at six months used peritoneal dialysis. Values for a previously validated comorbidity score were higher for patients on hemodialysis at baseline (4.0 vs. 3.1, P < 0.001), three months (3.7 vs. 3.2, P = 0.001), and six months (3.6 vs. 3.2, P = 0.005). The overall mortality was 41%. The unadjusted peritoneal dialysis/hemodialysis mortality hazard ratios were 0.65 (95% CI, 0. 51 to 0.83, P = 0.0005), 0.84 (95% CI, 0.66 to 1.06, P = NS), and 0. 83 (95% CI, 0.64 to 1.08, P = NS) based on the modality of dialysis in use at baseline, three months, and six months, respectively. When adjusted for age, sex, diabetes, cardiac failure, myocardial infarction, peripheral vascular disease, malignancy, and acuity of renal failure, the corresponding hazard ratios were 0.79 (95% CI, 0. 62 to 1.01, P = NS), 1.00 (95% CI, 0.78 to 1.28, P = NS), and 0.95 (95% CI, 0.73 to 1.24, P = NS). Adjustment for a previously validated comorbidity score resulted in hazard ratios of 0.74 (95% CI, 0.58 to 0.94, P = 0.01), 0.94 (95% CI, 0.74 to 1.19, P = NS), and 0.88 (95% CI, 0.68 to 1.13, P = NS) at baseline, three months, and six months. There was no survival advantage for either modality in any of the major subgroups defined by age, sex, or diabetic status.

CONCLUSIONS

The apparent survival advantage of peritoneal dialysis in Canada is due to lower comorbidity and a lower burden of acute onset end-stage renal disease at the inception of dialysis therapy. Hemodialysis and peritoneal dialysis, as practiced in Canada in the 1990s, are associated with similar overall survival rates.

Should all Pima Indians with type 2 diabetes mellitus be prescribed routine angiotensin-converting enzyme inhibition therapy to prevent renal failure?

OBJECTIVE

To determine how effective angiotensin-converting enzyme (ACE) inhibitors must be in preventing diabetic nephropathy to warrant early and routine therapy in all Pima Indians with type 2 diabetes mellitus.

DESIGN

A computerized medical decision analysis model was used to compare strategy 1, screening for microalbuminuria and treatment of incipient nephropathy as currently recommended with ACE inhibitor therapy, with strategy 2, a protocol wherein all patients were routinely administered an ACE inhibitor 1 year after diagnosis of type 2 diabetes mellitus. The model assumed that ACE inhibitors can block, at least in part, the pathogenic mechanisms responsible for early diabetic nephropathy (microalbuminuria).

RESULTS

The model predicted that strategy 2 would produce more life-years at less cost than strategy 1, if routine drug therapy reduced the rate of development of microalbuminuria by 21% in all patients. Only a 9% reduction in the rate of development of microalbuminuria was cost-effective at $15,000 per additional life-year gained, and only a 2.4% reduction was cost-effective at $75,000 per additional life-year gained for strategy 2 over strategy 1.

CONCLUSIONS

Routine ACE inhibitor therapy in Pima Indians with type 2 diabetes mellitus could prove more effective and even cost saving than the currently recommended approach of microalbuminuria screening. A prospective trial examining this goal should be considered.

Management of idiopathic crescentic and diffuse proliferative glomerulonephritis: evidence-based recommendations

Idiopathic crescentic glomerulonephritis (GN) often presents with a rapid loss of renal function and pathology showing extensive crescent formation. The disease is caused by different immunopathogenetic mechanisms, pauci-immune, often antineutrophil cytoplasmic antibody (ANCA)-positive microvasculitis, antiglomerular basement membrane (GBM) antibody disease, and immune complex formation. Historical reviews reveal poor renal prognosis, even after treatment with oral steroids and cytotoxic drugs. Prognosis has improved in the last decade. In this article, evidence-based recommendations for management are presented. Because of the high risk of end-stage renal disease (ESRD), early aggressive therapy is recommended, despite weak supporting evidence. Treatment for anti-GBM antibody-induced crescentic GN should be initiated early and should include pulse methylprednisolone, a two-week course of plasmapheresis and two months of treatment with corticosteroids and cyclophosphamide (grade B and C). Treatment for pauci-immune crescentic GN should be pulse methylprednisolone, followed by oral corticosteroids and cyclophosphamide for 6 to 12 months (grade B). Recurrences can be managed similarly (grade B), along with appropriate supportive therapy. In patients who develop ESRD, successful transplantation can be performed. Diffuse endocapillary proliferative GN is classically postinfectious. It generally has a good prognosis when no crescent formation occurs. Adult patients with persistent proteinuria, hypertension, and renal function impairment need careful follow-up and management to modify progressive hemodynamic injury.

Routine treatment of insulin-dependent diabetic patients with ACE inhibitors to prevent renal failure: an economic evaluation

The objective of this study was to determine how effective angiotensin-converting enzymes (ACEs) must be in preventing diabetic nephropathy to warrant routine administration to insulin-dependent diabetic patients. A Markov model was used to compare three strategies designed to prevent the development of end-stage renal disease in insulin-dependent diabetic patients. Strategy I, screening for microalbuminuria and treatment of incipient nephropathy as currently recommended, was compared with strategy II, a protocol in which patients were routinely administered an ACE inhibitor 5 years after diagnosis of diabetes, and strategy III, in which patients at high risk for nephropathy were routinely treated and low-risk patients followed a protocol in which patients were treated with an ACE inhibitor if they developed hypertension and/or macroproteinuria. The model predicted that strategy II would produce as many quality-adjusted life-years as strategy I at nearly the same cost if routine drug therapy reduced the rate of development of microalbuminuria by 26% in all patients. Strategy III produced as many quality-adjusted life-years at less cost than strategy I if a high-risk cohort could be identified with a rate of developing microalbuminuria at four times the rate of low-risk patients and if drug therapy reduced the rate of developing microalbuminuria in this high-risk group by 20%. In conclusion, routine ACE inhibitor therapy could prove to be cost-effective, especially if high-risk individuals could be identified. A prospective trial examining this goal should be considered.

Polyurethane catheters for long-term hemodialysis access

Chronic hemodialysis patients with failed native fistulas and/or synthetic arteriovenous grafts are usually dialyzed via surgically placed silicone jugular catheters such as the PermCath (Quinton, Seattle, WA, U.S.A.). We report a successful experience with the use of double lumen polyurethane central venous catheters placed percutaneously. Catheters with poor flows were replaced over a guidewire at the bedside. Eleven long-term hemodialysis patients failed arteriovenous access, 9 of them having had multiple attempts at fistulas and/or grafts. Seven of these patients had also failed peritoneal dialysis. They were dialyzed with polyurethane catheters for a mean of 681 +/- 280 days (range 282-1150 days), requiring a mean of 3.4 +/- 0.4 new venous punctures and 8.2 +/- 1.5 catheter changes over a guidewire over that period of time. Actuarial patient survival was 50% at 2 years, and mean urea reduction during dialysis was 64.2 +/- 1.7%. The septicemia rate was only 1.2 episodes per 1,000 catheter-days, but about 20% of patients experienced central venous occlusion, attributable to the use of subclavian catheter placement in 82% of the sites. The success of this technique and its elimination of the need for urokinase, radiologic interventions, and surgical placement warrant its consideration as an acceptable form of long-term vascular access, provided jugular placement allows reduced central venous occlusion rates.

Prediction of early death in end-stage renal disease patients starting dialysis

Demand for dialysis for patients with end-stage renal disease is growing, as is the comorbidity of dialysis patients. Accurate prediction of those destined to die quickly despite dialysis could be useful to patients, providers, and society in making decisions about starting dialysis. To determine whether age and comorbidity accurately predict death within 6 months of first dialysis for end-stage renal disease, a prospective cohort study of 822 patients starting dialysis at one of 11 Canadian centers was performed. Patient characteristics were recorded at first dialysis. Follow-up continued until death or study end (at least 6 months after enrollment). One hundred thirteen of 822 (13.7%) patients died within 6 months. Although an existing scoring system predicted prognosis, adverse scores greater than 9 were found in only 9.7% of those who died; only 52% of those who scored higher than 9 died within 6 months. No score cutoff point combined high true-positive and low false-positive rates for predicting early death. Age, severity of heart failure or peripheral vascular disease, arrhythmias, malnutrition, malignancy, or myeloma were independent prognostic factors identified in multivariate models. However, the best fit discriminant and logistic models were also unable to accurately predict death within 6 months. Clinicians were very accurate in assigning patients to prognostic groups up to a 50% risk of death by 6 months, above which they tended to overestimate risk. However, clinicians were only marginally better than the predictive models in determining whether a given high-risk patient would die. The inability of a scoring system or clinical intuition to accurately predict death soon after starting dialysis for end-stage renal disease suggests that limiting access to dialysis on the basis of likely short survival may be inappropriate in Canada.

Multicenter clinical validation of an on-line monitor of dialysis adequacy

Quantitation of hemodialysis by measuring changes in blood solute concentration requires careful timing when taking the postdialysis blood sample to avoid errors from postdialysis rebound and from recirculation of blood through the access device. It also requires complex mathematical interpretation to account for solute disequilibrium in the patient. To circumvent these problems, hemodialysis can be quantified and its adequacy assessed by direct measurement of the urea removed in the dialysate. Because total dialysate collection is impractical, an automated method was developed for measuring dialysate urea-nitrogen concentrations at frequent intervals during treatment. A multicenter clinical trial of the dialysate monitoring device, the Biostat 1000 (Baxter Healthcare Corporation, McGaw Park, IL) was conducted to validate the measurements of urea removed, the delivered dialysis dose (Kt/V), and net protein catabolism (PCR). The results were compared with a total dialysate collection in each patient. During 29 dialyses in 29 patients from three centers, the paired analysis of urea removed, as estimated by the dialysate monitor compared with the total dialysate collection, showed no significant difference (14.7 +/- 4.7 g versus 14.8 +/- 5.1 g). Similarly, measurements of Kt/V and PCR showed no significant difference (1.30 +/- 0.18 versus 1.28 +/- 0.19, respectively, for Kt/V and 42.3 +/- 15.7 g/day versus 52.2 +/- 17.4 g/day for PCR). When blood-side measurements during the same dialyses were analyzed with a single-compartment, variable-volume model of urea kinetics, Kt/V was consistently overestimated (1.49 +/- 0.29/dialysis, P < 0.001), most likely because of failure to consider urea disequilibrium. Because urea disequilibrium is difficult to quantitate during each treatment, dialysate measurements have obvious advantages. The dialysate monitor eliminated errors from dialysate bacterial contamination, simplified dialysate measurements, and proved to be a reliable method for quantifying and assuring dialysis adequacy.

Screening to prevent renal failure in insulin dependent diabetic patients: an economic evaluation

OBJECTIVE

To examine the conditions necessary to make screening for microalbuminuria in patients with insulin dependent diabetes mellitus cost effective.

DESIGN

This economic evaluation compared two strategies designed to prevent the development of end stage renal disease in patients with insulin dependent diabetes with disease for five years. Strategy A, screening for microalbuminuria as currently recommended, was compared with strategy B, a protocol in which patients were screened for hypertension and macroproteinuria.

INTERVENTION

Patients identified in both strategies were treated with an angiotensin converting enzyme inhibitor.

SETTING

Computer simulation.

MAIN OUTCOME MEASURES

Strategy costs and quality adjusted life years (QALYs).

RESULTS

The model predicted that strategy A would produce an additional 0.00967 QALYs at a present value cost of $261.53 (1990 US$) per patient (or an incremental cost/QALY of $27,041.69) over strategy B. The incremental cost/QALY for strategy A over B was sensitive to several variables. If the positive predictive value of screening for microalbuminuria (impact of false label and unnecessary treatment) is < 0.72, the effect of treatment to delay progression from microalbuminuria to macroproteinuria is < 1.6 years, the cumulative incidence of diabetic nephropathy falls to < 20%, or > 64% of patients demonstrate hypertension at the onset of microalbuminuria, then the incremental costs/QALY will exceed $75,000.

CONCLUSION

Whether microalbuminuria surveillance in this population is cost effective requires more information. Being aware of the costs, recommendation pitfalls, and gaps in our knowledge should help focus our efforts to provide cost effective care to this population.

Evidence-based recommendations for the clinical use of recombinant human erythropoietin

In an era of increasing scrutiny regarding use of health care resources, it is critical that physicians have rational, evidence-based guidelines for treatment decisions. This review of more than 200 published papers constitutes a comprehensive approach to evaluating the current evidence regarding the clinical use of recombinant human erythropoietin therapy in renal failure patients. After this review, specific recommendations are provided regarding who should receive r-HuEPO; what the target hemoglobin should be; the best route of administration of r-HuEPO; how iron status should be evaluated and managed; and monitoring and follow-up of patients taking r-HuEPO. Throughout the article, areas for important future research are also identified.

Experience with not offering dialysis to patients with a poor prognosis

Despite ongoing discussion of dialysis rationing in the nephrology community, there are little available data describing current practice in treatment selection for very ill renal patients with a poor prognosis. We report a prospective survey of end-stage renal patients referred to our Canadian regional dialysis center who were not accepted to the dialysis program on the grounds of poor prognosis and low quality of life. One quarter of patients referred during 1992 were not accepted to the program, with a mean age of 74 +/- 11 years. Patients were predominantly female and most suffered from a combination of renovascular and cardiovascular disease, with very poor functional capacity as determined by the Karnofsky scale. Nonacceptance to the dialysis program did not create legal difficulties or requests for second opinions. Based on our experience, we propose guidelines for nonacceptance of patients to dialysis programs.

Low-dose subcutaneous erythropoietin corrects the anaemia of renal transplant failure

Although erythropoietin (Epo) is known to correct anaemia in dialysis and pre-dialysis patients, there is limited experience with its use in immunosuppressed patients suffering from chronic renal graft dysfunction. We report the results of a pilot study of Epo in seven patients with failing grafts and normocytic normochromic anaemia attributable to renal failure. All entering patients had controlled blood pressure and serum ferritin greater than 100 micrograms/l. Three patients were taking triple immunotherapy (prednisone/azathioprine/cyclosporin), two patients prednisone/azathioprine, and two patients CsA monotherapy. Study duration mean was 15 +/- 2 (SEM) weeks, and Epo was started at 4000 units subcutaneously (s.c.) once weekly, adjusted to achieve a target haemoglobin (Hb) of 100 g/l. Mean Hb at initiation was 68 +/- 5 g/l and significantly increased to 96 +/- 6 at end of follow-up, P less than 10(-4). All patients responded. Maintenance Epo dosage was 120 +/- 32 U/kg bodyweight/week, roughly 4000 units/week. There was no significant change in serum creatinine: pre-study 392 +/- 45 mumol/l; post-study 430 +/- 62 mumol/l. There were no complications but blood pressure did rise significantly: pre- 124 +/- 11/74 +/- 4 mmHg to post- 142 +/- 10/86 +/- 3, P less than 0.05 for systolic and diastolic. Low-dose s.c. Epo effectively corrects anaemia in graft failure despite azathioprine and/or CsA therapy, without obvious acceleration of graft failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of hemodialysis subclavian vein catheter infections by topical povidone-iodine

Subclavian catheter (SCC) related infections are a major cause of morbidity in hemodialysis patients, the vast majority due to staphylococci species. Povidone-iodine (PI) has proven anti-staphylococcal activity. Therefore, a randomized controlled trial of topical PI ointment was undertaken to evaluate the impact of this prophylactic intervention on the incidence of SCC related infections in hemodialysis patients. The role of S. aureus nasal carrier state in the acquisition of infection was also evaluated. Patients requiring SCC for temporary hemodialysis access were randomized to receive the treatment (T; N = 63) or sterile gauze dressings alone (C; N = 66). Catheter duration ranged from 2 to 210 days in both groups, with a mean of 38.6 days in T and 36.2 days in C (NS). Exit site (ES) infections were significantly less in T (5%) versus C (18%) (P less than 0.02); tip colonization (TC) was 17% in T versus 36% in C (P less than 0.01), while the incidence of septicemia (S) was also significantly less in T (2%) versus C (17%; P less than 0.01). S. aureus nasal carriers were at a threefold higher risk of SCC related septicemia (0.009/day) than noncarriers (0.003/day; P less than 0.05). The beneficial effect of PI ointment was most evident in this high risk group of S. aureus carriers: ES = 0% T versus 24% C, TC = 12% T versus 42% C, S = 0% T versus 29% C, P less than 0.05. There were no adverse effects of the treatment. The routine application of topical PI ointment to temporary hemodialysis catheter exit sites is effective in reducing SCC related infections.