The cost-utility of haemodiafiltration versus haemodialysis in the Convective Transport Study

The health and budget impact of sodium-glucose co-transporter-2 inhibitors (SGLT2is) in the Netherlands

OBJECTIVES

Type-2 Diabetes Mellitus (T2DM) increases both the patient risk of cardiovascular disease (CVD) and renal outcomes, such as chronic kidney disease (CKD). Recent clinical trials of the glucose-lowering drug-class of sodium-glucose co-transporter-2 inhibitors (SGLT2is) have shown benefits in preventing CVD events and progression of CKD, leading to an update of the Dutch T2DM treatment guideline for patients at risk. The aim of this study is to assess the health and economic impact of the guideline-recommended utilisation of SGLT2is in the Netherlands.

METHODS

The patient population at risk was determined by multiplying Dutch T2DM prevalence rates with the total numbers of inhabitants of the Netherlands in 2020. Subsequently, two analyses, comparing a treatment setting before and after implementation of the new guideline for SGLT2is, were conducted. Clinical and adverse event rates in both settings as well as direct healthcare costs were sourced from the literature. Total costs were calculated by multiplying disease prevalence, event rates and costs associated to outcomes. One-time disutilities per event were included to estimate the health impact. The potential health and economic impact of implementing the updated guideline was calculated.

RESULTS

Using a 5-year time horizon, the guideline-suggested utilisation of SGLT2is resulted in a health impact equal to 4,835 quality adjusted life years gained (0.0031 per patient per year) and €461 million cost-savings. The costs of treatment with SGLT2is were €813 million. Hence the net budget impact was €352 million for the total Dutch T2DM population, which translated to €0,57 per patient per day.

CONCLUSION

SGLT2is offer an option to reduce the number of CVD and CKD related events and associated healthcare costs and health losses in the Netherlands. Further research is needed to include the benefits of improved T2DM management options from a broader societal perspective.

Systematic review to compare the outcomes associated with the modalities of expanded hemodialysis (HDx) versus high-flux hemodialysis and/or hemodiafiltration (HDF) in patients with end-stage kidney disease (ESKD)

BACKGROUND

This systematic review was performed to identify recent published comparative evidence on the efficacy, effectiveness, and safety of expanded hemodialysis (HDx) versus high-flux HD and/or hemodiafiltration (HDF) for long-term outcomes in end-stage kidney disease.

METHODS

Systematic literature review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Medline, Medline® Epub Ahead of Print, EconLit, Embase, and EBM reviews were searched to identify relevant publications from 2013 onwards. Eligibility criteria included clinical studies reporting mortality, hospitalizations, cardiovascular outcomes, economic evaluations, cost studies, and quality of life (QoL) studies.

RESULTS

A total of 79 relevant studies were identified with 29 prioritized for detailed analysis; four compared HDx to HD, one compared HDF and HDx, and 24 compared HDF with HD. A total of 13 randomized controlled trial (RCT)-based studies were identified; 11 compared HDF with HD, one compared HDx with HD, and one compared HDF with HDx. Follow-up duration ranged from 16 weeks to 7 years for HDF studies and from 12 weeks to 1 year for HDx studies. HDF showed significant improvements in mortality, cardiovascular outcomes, hospitalizations, and QoL versus high-flux HD. One study reported mortality outcomes for HDx and found no difference versus HDF. QoL benefits with HDx were reported in a small number of studies.

CONCLUSION

The efficacy and safety of HDF is supported by a robust evidence base that includes several RCTs. While HDx may offer benefits over high-flux HD, long-term studies are required to compare HDx with online high volume HDF.

REGISTRATION

PROSPERO registration number: CRD42022301009.

Timing of dialysis initiation to reduce mortality and cardiovascular events in advanced chronic kidney disease: nationwide cohort study

OBJECTIVE

To identify the optimal estimated glomerular filtration rate (eGFR) at which to initiate dialysis in people with advanced chronic kidney disease.

DESIGN

Nationwide observational cohort study.

SETTING

National Swedish Renal Registry of patients referred to nephrologists.

PARTICIPANTS

Patients had a baseline eGFR between 10 and 20 mL/min/1.73 m2 and were included between 1 January 2007 and 31 December 2016, with follow-up until 1 June 2017.

MAIN OUTCOME MEASURES

The strict design criteria of a clinical trial were mimicked by using the cloning, censoring, and weighting method to eliminate immortal time bias, lead time bias, and survivor bias. A dynamic marginal structural model was used to estimate adjusted hazard ratios and absolute risks for five year all cause mortality and major adverse cardiovascular events (composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) for 15 dialysis initiation strategies with eGFR values between 4 and 19 mL/min/1.73 m2 in increments of 1 mL/min/1.73 m2. An eGFR between 6 and 7 mL/min/1.73 m2 (eGFR6-7) was taken as the reference.

RESULTS

Among 10 290 incident patients with advanced chronic kidney disease (median age 73 years; 3739 (36%) women; median eGFR 16.8 mL/min/1.73 m2), 3822 started dialysis, 4160 died, and 2446 had a major adverse cardiovascular event. A parabolic relation was observed for mortality, with the lowest risk for eGFR15-16. Compared with dialysis initiation at eGFR6-7, initiation at eGFR15-16 was associated with a 5.1% (95% confidence interval 2.5% to 6.9%) lower absolute five year mortality risk and 2.9% (0.2% to 5.5%) lower risk of a major adverse cardiovascular event, corresponding to hazard ratios of 0.89 (95% confidence interval 0.87 to 0.92) and 0.94 (0.91 to 0.98), respectively. This 5.1% absolute risk difference corresponded to a mean postponement of death of 1.6 months over five years of follow-up. However, dialysis would need to be started four years earlier. When emulating the intended strategies of the Initiating Dialysis Early and Late (IDEAL) trial (eGFR10-14 v eGFR5-7) and the achieved eGFRs in IDEAL (eGFR7-10 v eGFR5-7), hazard ratios for all cause mortality were 0.96 (0.94 to 0.99) and 0.97 (0.94 to 1.00), respectively, which are congruent with the findings of the randomised IDEAL trial.

CONCLUSIONS

Very early initiation of dialysis was associated with a modest reduction in mortality and cardiovascular events. For most patients, such a reduction may not outweigh the burden of a substantially longer period spent on dialysis.

Patient, family and productivity costs of end-stage renal disease in the Netherlands; exposing non-healthcare related costs

Background

Healthcare costs related to ESRD are well-described, but broader societal costs of ESRD are less known. This study aimed to estimate patient and family costs, including informal care costs and out-of-pocket costs, and costs due to productivity loss related to ESRD, for patients receiving dialysis and living with a kidney transplant, using a bottom-up approach.

Methods

A total of 655 patients were asked to complete a digital questionnaire consisting of two standardised instruments (iMCQ and iPCQ) from November 2016 through January 2017. We applied a retrospective bottom-up cost estimation by combining data from the questionnaire with unit prices from the Dutch costing manual.

Results

Our study sample consisted of 230 patients, of which 165 were kidney transplant recipients and 65 received dialysis. The total annual non-healthcare related costs were estimated at €8284 (SD: €14,266) for transplant recipients and €23,488 (SD: €39,434) for dialysis patients. Costs due to productivity loss contributed most to the total non-healthcare costs (66% for transplant recipients and 65% for dialysis patients), followed by informal care costs (26% resp. 29%) and out-of-pocket costs, such as medication and travel expenses (8% resp. 6%).

Conclusion

By exposing patient, family and productivity costs, our study revealed that dialysis and transplantation are not only costly within the healthcare system, but also incur high non-healthcare costs (18–23% resp. 35% of the total societal costs). It is important to reveal these types of non-healthcare costs in order to understand the full burden of ESRD for society and the potential impact of new therapies.

An initial evaluation of expanded hemodialysis on hospitalizations, drug utilization, costs, and patient utility in Colombia

To examine new evidence linking expanded hemodialysis (HDx) using a medium cut‐off (MCO) membrane with hospitalizations, hospital days, medication use, costs, and patient utility. This retrospective study utilized data from Renal Care Services medical records database in Colombia from 2017 to 2019. Clinics included had switched all patients from high flux hemodialysis (HD HF) to HDx and had at least a year of data on HD HF and HDx. Data included demographic characteristics, comorbidities, years on dialysis, hospitalizations, medication use, and quality of life measured by the 36 item and Short Form versions of the Kidney Disease Quality of Life survey at the start of HDx, and 1 year after HDx, which were mapped to EQ‐5D utilities. Generalized linear models were run on the outcomes of interest with an indicator for being on HDx. Annual cost estimates were also constructed. The study included 81 patients. HDx was significantly associated with lower dosing of erythropoietin stimulating agents, iron, hypertension medications, and insulin. HDx was also significantly associated with lower hospital days per year (5.94 on HD vs. 4.41 on HDx) although not with the number of hospitalizations. Estimates of annual hospitalization costs were 23.9% lower using HDx and patient utilities did not appear to decline. HDx was statistically significantly associated with reduced hospitalization days and lower medication dosages. Furthermore, this preliminary analysis suggested potential for HDx being a dominant strategy in terms of costs and utility and should motivate future work with larger samples and better controls.

Online hemodiafilteration use in children: a single center experience with a twist

Background

Haemodiafilteration (HDF) is a promising new modality of renal replacement therapy (RRT). It is an improvement in the quality of hemodialysis (HD) and thus in the quality of patients’lives. The main obstacle to using HDF is the cost, especially in developing countries. The purpose of this study was to evaluate the benefits of incorporating HDF with different regimens in the treatment of children with end stage renal disease (ESRD).

Methods

Thirty-four children with ESRD on regular HD in Pediatric Dialysis Unit, Children’s Hospital, Ain Shams University were followed up in 2 phases: initial phase (all patients: HD thrice weekly for 3 months) and second phase, patients were randomized into 2 groups, HDF group and HD group, the former was subdivided into once and twice weekly HDF subgroups. Evaluation using history, clinical and laboratory parameters at 0, 3, 9 and 18 months was carried out.

Results

On short term, we found that the HDF group was significantly superior to HD group regarding all clinical and laboratory parameters. Also, twice HDF subgroup was significantly superior to once HDF subgroup. This was confirmed on long term follow up, but the once HDF proved comparable to twice subgroup.

Conclusions

Incorporating online hemodiafilteration (OL-HDF) in the RRT of children was beneficial in most of the clinical and laboratory parameters measured. It’s not all or non; OL-HDF, even once a week, can improve outcomes of HD without significantly affecting the cost.

Costs of clinical events in type 2 diabetes mellitus patients in the Netherlands: A systematic review

BACKGROUND

Type 2 diabetes mellitus (T2DM) is an established risk factor for cardiovascular and nephropathic events. In the Netherlands, prevalence of T2DM is expected to be as high as 8% by 2025. This will result in significant clinical and economic impact, highlighting the need for well-informed reimbursement decisions for new treatments. However, availability and consistent use of costing methodologies is limited.

OBJECTIVE

We aimed to systematically review recent costing data for T2DM-related cardiovascular and nephropathic events in the Netherlands.

METHODS

A systematic literature review in PubMed and Embase was conducted to identify available Dutch cost data for T2DM-related events, published in the last decade. Information extracted included costs, source, study population, and costing perspective. Finally, papers were evaluated using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS).

RESULTS

Out of initially 570 papers, 36 agreed with the inclusion criteria. From these studies, 150 cost estimates for T2DM-related clinical events were identified. In total, 29 cost estimates were reported for myocardial infarction (range: €196-€27,038), 61 for stroke (€495-€54,678), fifteen for heart failure (€325-€16,561), 24 for renal failure (€2,438-€91,503), and seventeen for revascularisation (€3,000-€37,071). Only four estimates for transient ischaemic attack were available, ranging from €587 to €2,470. Adherence to CHEERS was generally high.

CONCLUSIONS

The most expensive clinical events were related to renal failure, while TIA was the least expensive event. Generally, there was substantial variation in reported cost estimates for T2DM-related events. Costing of clinical events should be improved and preferably standardised, as accurate and consistent results in economic models are desired.

Healthcare costs of patients on different renal replacement modalities – Analysis of Dutch health insurance claims data

Background

The aim of this study is to present average annual healthcare costs for Dutch renal replacement therapy (RRT) patients for 7 treatment modalities.

Methods

Health insurance claims data from 2012–2014 were used. All patients with a 2014 claim for dialysis or kidney transplantation were selected. The RRT related and RRT unrelated average annual healthcare costs were analysed for 5 dialysis modalities (in-centre haemodialysis (CHD), home haemodialysis (HHD), continuous ambulatory peritoneal dialysis (CAPD), automated peritoneal dialysis (APD) and multiple dialysis modalities in a year (Mix group)) and 2 transplant modalities (kidney from living and deceased donor, respectively).

Results

The total average annual healthcare costs in 2014 ranged from €77,566 (SD = €27,237) for CAPD patients to €105,833 (SD = €30,239) for patients in the Mix group. For all dialysis modalities, the vast majority (72–84%) of costs was RRT related. Patients on haemodialysis ≥4x/week had significantly higher average annual costs compared to those dialyzing 3x/week (Δ€19,122). Costs for kidney transplant recipients were €85,127 (SD = €39,679) in the year of transplantation and rapidly declined in the first and second year after successful transplantation (resp. €29,612 (SD = €34,099) and €15,018 (SD = €16,186)). Transplantation with a deceased donor kidney resulted in higher costs (€99,450, SD = €36,036)) in the year of transplantation compared to a living donor kidney transplantation (€73,376, SD = €38,666).

Conclusions

CAPD patients have the lowest costs compared to other dialysis modalities. Costs in the year of transplantation are 25% lower for patients with kidneys from living vs. deceased donor. After successful transplantation, annual costs decline substantially to a level that is approximately 14–19% of annual dialysis costs.

Impact of Regular or Extended Hemodialysis and Hemodialfiltration on Plasma Oxalate Concentrations in Patients With End-Stage Renal Disease

Introduction

Calcium oxalate supersaturation is regularly exceeded in the plasma of patients with end-stage renal disease (ESRD). Previous reports have indicated that hemodialfiltration (HDF) lowers elevated plasma oxalate (P_Ox) concentrations more effectively compared with hemodialysis (HD). We reevaluate the therapeutic strategy for optimized P_Ox reduction with advanced dialysis equipment and provide data on the effect of extended treatment time on dialytic oxalate kinetics.

Methods

Fourteen patients with ESRD who underwent HDF 3 times a week for 4 to 4.5 hours (regular HDF; n = 8) or 7 to 7.5 hours (extended HDF; n = 6) were changed to HD for 2 weeks and then back to HDF for another 2 weeks. P_Ox was measured at baseline, pre-, mid-, and postdialysis, and 2 hours after completion of the treatment session.

Results

Baseline P_Ox for all patients averaged 28.0 ± 7.0 μmol/l. Intradialytic P_Ox reduction was approximately 90% and was not significantly different between groups or treatment modes [F(1) = 0.63; P = 0.44]. Mean postdialysis P_Ox concentrations were 3.3 ± 1.8 μmol/l. A rebound of 2.1 ± 1.9 μmol/l was observed within 2 hours after dialysis. After receiving 2 weeks of the respective treatment, predialysis P_Ox concentrations on HD did not differ significantly from those on HDF [F(1) = 0.21; P = 0.66]. Extended treatment time did not provide any added benefit [F(1) = 0.76; P = 0.40].

Discussion

In contrast to earlier observations, our data did not support a benefit of HDF over HD for P_Ox reduction. With new technologies evolving, our results emphasized the need to carefully reevaluate and update traditional therapeutic regimens for optimized uremic toxin removal, including those used for oxalate.

Cost-Effectiveness of High Dose Hemodialysis in Comparison to Conventional In-Center Hemodialysis in the Netherlands

INTRODUCTION

In the Netherlands, the current standard of care for treating patients with end-stage renal disease is three sessions of in-center hemodialysis (conventional ICHD). However, the literature indicates that high dose hemodialysis (high dose HD) may provide better health outcome such as survival and quality of life. The objective of this study was to determine the cost-effectiveness of high dose HD, both in-center and at home, in comparison to conventional ICHD from a Dutch payer's perspective over a 5 year period. Additionally, the cost-effectiveness of conventional HD at home in comparison to conventional ICHD will be analysed.

METHODS

A Markov model was developed assuming 28-day treatment cycles and was populated with data from Dutch and international renal registries, official tariffs and medical literature. Univariable and probabilistic sensitivity analyses were performed to test the robustness of the results.

RESULTS

Using publicly available tariffs from the Dutch Healthcare Authority (Nederlandse Zorgautoriteit) of 2015, doing high dose ICHD instead of conventional ICHD shows an incremental cost-effectiveness ratio (ICER) of €275,747 per quality-adjusted life year (QALY) gained. In contrast, the ICER of high dose HD at home in comparison to conventional ICHD is €3248 per gained QALY. The final analysis shows that conventional HD at home is less costly per patient (-€3063) than conventional ICHD and results in health benefit improvement (+0.249 QALYs), and is therefore regarded as cost saving.

CONCLUSION

Treating dialysis patients with conventional HD at home shows to be cost saving in comparison to conventional ICHD. However, the magnitude of clinical benefit of high dose HD at home is over two times greater than the clinical benefit of conventional HD at home. According to our analysis, from a payer's perspective, high dose HD should be offered as a home therapy to obtain its clinical benefits in a cost-effective manner. Future research should consider our findings alongside societal factors, such as patient preference, monitoring cost for the home patient, productivity loss and capacity.

FUNDING

Baxter BV, The Netherlands.

Cost-effectiveness analysis of online hemodiafiltration versus high-flux hemodialysis

Background

Clinical studies suggest that hemodiafiltration (HDF) may lead to better clinical outcomes than high-flux hemodialysis (HF-HD), but concerns have been raised about the cost-effectiveness of HDF versus HF-HD. Aim of this study was to investigate whether clinical benefits, in terms of longer survival and better health-related quality of life, are worth the possibly higher costs of HDF compared to HF-HD.

Methods

The analysis comprised a simulation based on the combined results of previous published studies, with the following steps: 1) estimation of the survival function of HF-HD patients from a clinical trial and of HDF patients using the risk reduction estimated in a meta-analysis; 2) simulation of the survival of the same sample of patients as if allocated to HF-HD or HDF using three-state Markov models; and 3) application of state-specific health-related quality of life coefficients and differential costs derived from the literature. Several Monte Carlo simulations were performed, including simulations for patients with different risk profiles, for example, by age (patients aged 40, 50, and 60 years), sex, and diabetic status. Scatter plots of simulations in the cost-effectiveness plane were produced, incremental cost-effectiveness ratios were estimated, and cost-effectiveness acceptability curves were computed.

Results

An incremental cost-effectiveness ratio of €6,982/quality-adjusted life years (QALY) was estimated for the baseline cohort of 50-year-old male patients. Given the commonly accepted threshold of €40,000/QALY, HDF is cost-effective. The probabilistic sensitivity analysis showed that HDF is cost-effective with a probability of ~81% at a threshold of €40,000/QALY. It is fundamental to measure the outcome also in terms of quality of life. HDF is more cost-effective for younger patients.

Conclusion

HDF can be considered cost-effective compared to HF-HD.

A comparison of self-reported quality of life for an Australian haemodialysis and haemodiafiltration cohort

AIMS

Haemodiafiltration (HDF) has been widely studied for evidence of superior outcomes in comparison with conventional haemodialysis (HD), and there is increasing interest in determining if HDF confers any benefit in relation to quality of life. Studies have been conducted with randomized incident patients; however, little is known regarding HDF and quality of life for prevalent patients. This study examined and compared self-reported quality of life at two time points, 12 months apart in a cohort of satellite HD and HDF patients, using a disease specific questionnaire to determine if HDF conferred an advantage.

METHODS

A longitudinal study with a linear mixed-effect model measuring quality of life in a cohort of 171 patients (HD, n = 85, HDF, n = 86) in seven South Australian satellite dialysis centres.

RESULTS

Factors associated with significant reduction across the Kidney Disease Quality Of Life™ domains measured were younger age (- 20 to - 29) and comorbid diabetes (- 4.8 to - 11.1). HDF was not associated with moderation of this reduction at either time point (P > 0.05). Baseline physical functioning was reported as very low (median 33.9) and further reduced at time point two. In addition, dialysing for more than 12 h per week in a satellite dialysis unit was associated with reduced quality of life in relation to the burden of kidney disease (- 13.69).

CONCLUSION

This study has demonstrated that younger age and comorbid diabetes were responsible for a statistically significant reduction in quality of life, and HDF did not confer any advantage.

Dynamics of the erythropoiesis stimulating agent resistance index in incident hemodiafiltration and high-flux hemodialysis patients

Hyporesponsiveness to erythropoiesis-stimulating agent therapy in dialysis patients is poorly understood. Some studies report an improvement in the erythropoiesis-stimulating agent resistance index (ERI) with hemodiafiltration (HDF) versus high-flux hemodialysis (HD). We explored ERI dynamics in 38,340 incident HDF and HD patients treated in 22 countries over a 7-year period. Groups were matched by propensity score at baseline (6 months after dialysis initiation). The follow-up period (mean of 1.31 years) was stratified into 1 month intervals with delta analyses performed for key ERI-related parameters. Dialysis modality, time interval, and polycystic kidney disease were included in a linear mixed model with the outcome ERI. Baseline ERI was nonsignificantly higher in HDF versus HD treatment. ERI decreased significantly faster in HDF-treated patients than in HD-treated patients, was decreased in both HD and HDF when patients were treated with intravenous darbepoetin alfa, but only in HDF when treated with intravenous recombinant human erythropoietin (rHuEPO). A clear difference between HD- and HDF-treated patients could only be found for patients with high baseline ERI and assigned to intravenous rHuEPO treatment. A significant advantage in terms of lower ERI for patients treated by HDF was found. Sensitivity analysis limited this advantage for HDF to those patients treated with intravenous rHuEPO (not darbepoetin alfa or subcutaneous rHuEPO) and to patients with a high baseline ERI. Thus, our results allow more accurate planning for future clinical trials addressing anemia management in dialysis patients.

Cost-Effectiveness Analysis of High-Efficiency Hemodiafiltration Versus Low-Flux Hemodialysis Based on the Canadian Arm of the CONTRAST Study

AIM

The aim of this study was to assess the cost effectiveness of high-efficiency on-line hemodiafiltration (OL-HDF) compared with low-flux hemodialysis (LF-HD) for patients with end-stage renal disease (ESRD) based on the Canadian (Centre Hospitalier de l'Université de Montréal) arm of a parallel-group randomized controlled trial (RCT), the CONvective TRAnsport STudy.

METHODS

An economic evaluation was conducted for the period of the RCT (74 months). In addition, a Markov state transition model was constructed to simulate costs and health benefits over lifetime. The primary outcome was costs per quality-adjusted life-year (QALY) gained. The analysis had the perspective of the Quebec public healthcare system.

RESULTS

A total of 130 patients were randomly allocated to OL-HDF (n = 67) and LF-HD (n = 63). The cost-utility ratio of OL-HDF versus LF-HD was Can$53,270 per QALY gained over lifetime. This ratio was fairly robust in the sensitivity analysis. The cost-utility ratio was lower than that of LF-HD compared with no treatment (immediate death), which was Can$93,008 per QALY gained.

CONCLUSIONS

High-efficiency OL-HDF can be considered a cost-effective treatment for ESRD in a Canadian setting. Further research is needed to assess cost effectiveness in other settings and healthcare systems.

High convection volume in online post-dilution haemodiafiltration: relevance, safety and costs

Increasing evidence suggests that treatment with online post-dilution haemodiafiltration (HDF) improves clinical outcome in patients with end-stage kidney disease, if compared with haemodialysis (HD). Although the primary analyses of three large randomized controlled trials (RCTs) showed inconclusive results, post hoc analyses of these and previous observational studies comparing online post-dilution HDF with HD showed that the risk of overall and cardiovascular mortality is lowest in patients who are treated with high-volume HDF. As such, the magnitude of the convection volume seems crucial and can be considered as the ‘dose’ of HDF. In this narrative review, the relevance of high convection volume in online post-dilution HDF is discussed. In addition, we briefly touch upon some safety and cost issues.

Haemodiafiltration, haemofiltration and haemodialysis for end-stage kidney disease

BACKGROUND

Convective dialysis modalities (haemofiltration (HF), haemodiafiltration (HDF), and acetate-free biofiltration (AFB)) removed excess body fluid across the dialysis membrane with positive pressure and accumulated middle- and larger-size accumulated solutes more efficiently than haemodialysis (HD). This increased larger solute removal combined with use of ultra-pure dialysis fluid in convective dialysis is hypothesised to reduce the frequency and severity of symptoms during dialysis as well as improve clinical outcomes. Convective dialysis therapies (HDF and HF) are associated with lower mortality compared to diffusive therapy (HD) in observational studies. This is an update of a review first published in 2006.

OBJECTIVES

To compare convective (HF, HDF, or AFB) with diffusive (HD) dialysis modalities on clinical outcomes (mortality, major cardiovascular events, hospitalisation and treatment-related adverse events) in men and women with end-stage kidney disease (ESKD).

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register (to 18 February 2015) through contact with a Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials comparing convective therapy (HF, HDF, AFB) with another convective therapy or diffusive therapy (HD) for treatment of ESKD.

DATA COLLECTION AND ANALYSIS

Two independent authors identified studies, extracted data and assessed study risk of bias. We summarised treatment effects using the random effects model. We reported results as a risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous data together with 95% confidence intervals (CI). We assessed for heterogeneity using the Chi(2) test and explored the amount of variation in treatment estimates beyond that expected by chance using the I(2) statistic.

MAIN RESULTS

Twenty studies comprising 667 participants were included in the 2006 review. In that review, there was insufficient evidence of treatment effects on major clinical outcomes to draw clinically meaningful conclusions. Searching to February 2015 identified 40 eligible studies comprising 3483 participants overall. In total, 35 studies (4039 participants) compared HF, HDF or AFB with HD, three studies (54 participants) compared AFB with HDF, and three studies (129 participants) compared HDF with HF.Risks of bias in all studies were generally high resulting in low confidence in estimated treatment effects. Convective dialysis had no significant effect on all-cause mortality (11 studies, 3396 participants: RR 0.87, 95% CI 0.72 to 1.05; I(2) = 34%), but significantly reduced cardiovascular mortality (6 studies, 2889 participants: RR 0.75, 95% CI 0.61 to 0.92; I(2) = 0%). One study reported no significant effect on rates of nonfatal cardiovascular events (714 participants: RR 1.14, 95% CI 0.86 to 1.50) and two studies showed no significant difference in hospitalisation (2 studies, 1688 participants: RR 1.23, 95% CI 0.93 to 1.63; I(2) = 0%). One study reported rates of hypotension during dialysis were significantly reduced with convective therapy (906 participants: RR 0.72, 95% CI 0.66 to 0.80). Adverse events were not systematically evaluated in most studies and data for health-related quality of life were sparse. Convective therapies significantly reduced predialysis levels of B2 microglobulin (12 studies, 1813 participants: MD -5.55 mg/dL, 95% CI -9.11 to -1.98; I(2) = 94%) and increased dialysis dose (Kt/V urea) (14 studies, 2022 participants: MD 0.07, 95% CI -0.00 to 0.14; I(2) = 90%) compared to diffusive therapy, but results across studies were very heterogeneous. Sensitivity analyses limited to studies comparing HDF with HD showed very similar results. Directly comparative data for differing types of convective dialysis were insufficient to draw conclusions.Studies had important risks of bias leading to low confidence in the summary estimates and were generally limited to patients who had adequate dialysis vascular access.

AUTHORS' CONCLUSIONS

Convective dialysis may reduce cardiovascular but not all-cause mortality and effects on nonfatal cardiovascular events and hospitalisation are inconclusive. However, any treatment benefits of convective dialysis on all patient outcomes including cardiovascular death are unreliable due to limitations in study methods and reporting. Future studies which assess treatment effects of convection dose on patient outcomes including mortality and cardiovascular events would be informative.

Online-haemodiafiltration vs. conventional haemodialysis: a cross-over study

BACKGROUND

The main short-term advantages of haemodiafiltration (HDF) are supposedly better removal of Beta2-microglobulin (ß2-m) and phosphate, and better haemodynamic stability. The main disadvantage is higher costs. The aim of the study was to compare the clinical and biological parameters associated with HDF and high-flux haemodialysis (HD), using a cross-over design, while maintaining the same dialysis parameters.

METHODS

All patients on a 3 × 4 hours schedule were observed during 3 identical 6-months periods: HDF1 - HD - HDF2. The mean values for the 2 last months of each period were compared.

RESULTS

A total of 51 patients (76 % males, 45 % diabetic) with a mean age of 74 ± 15 years, and who had been on dialysis for 49 ± 60 months were included. The mean blood flow (329 ± 27 ml/min), dialysate flow (500 ml/min), and convection volumes (21.6 ± 3.2 L) were recorded. Patient medications were not changed. Predialysis blood pressure, phosphataemia, calcaemia, iPTH, Kt/V, nPNA and intradialytic events were similar throughout the 3 periods. Only serum albumin (34. 4 ± 3.6, 35.9 ± 3.4, 34.1 ± 4 g/L, p < 0. 0001) and ß2-m serum levels (26.1 ± 5.4, 28 ± 6, 26.5 ± 5 mg/L, p < 0.001, values shown for HDF1, HD, HDF2, respectively) were significantly lower during the HDF periods. Factor associated with higher delta serum albumin levels between HD and HDF periods was mainly a lower convection volume.

CONCLUSION

Comparing HDF and HD, we did not observe any differences in haemodynamic stability or in serum phosphate levels. Only serum ß2-m (-6% vs. HD) and albumin (-5% vs. HD) levels changed. The long-term clinical consequences of these biochemical differences should be prospectively assessed.