Global differences in dialysis modality mix: the role of patient characteristics, macroeconomics and renal service indicators.

BACKGROUND: An increase in the dialysis programme expenditure is expected in most countries given the continued rise in the number of people with end-stage renal disease (ESRD) globally. Since chronic peritoneal dialysis (PD) therapy is relatively less expensive compared with haemodialysis (HD) and because there is no survival difference between PD and HD, identifying factors associated with PD use is important. METHODS: Incidence counts for the years 2003-05 were available from 36 countries worldwide. We studied associations of population characteristics, macroeconomic factors and renal service indicators with the percentage of patients on PD at Day 91 after starting dialysis. With linear regression models, we obtained relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: The median percentage of incident patients on PD was 12% (interquartile range: 7-26%). Determinants independently associated with lower percentages of patients on PD were as follows: patients with diabetic kidney disease (per 5% increase) (RR 0.93; 95% CI 0.89-0.97), health expenditure as % gross domestic product (per 1% increase) (RR 0.93; 95% CI 0.87-0.98), private-for-profit share of HD facilities (per 1% increase) (RR 0.996; 95% CI 0.99-1.00; P = 0.04), costs of PD consumables relative to staffing (per 0.1 increase) (RR 0.97; 95% CI 0.95-0.99). CONCLUSIONS: The factors associated with a lower percentage of patients on PD include higher diabetes prevalence, higher healthcare expenditures, larger share of private-for-profit centres and higher costs of PD consumables relative to staffing. Whether dialysis modality mix can be influenced by changing healthcare organization and funding requires additional studies.

Translating chronic kidney disease epidemiology into patient care--the individual/public health risk paradox.

BACKGROUND: Applying the Kidney Disease Outcomes Quality Initiative definitions of chronic kidney disease (CKD), it appears that CKD is common. The increased recognition of CKD has brought with it the clinical challenge of translating into practice the implications for the patient and for service planning. To understand the clinical relevance and translate that into information to support individual patient care and service planning, we explored clinical outcomes in a large British CKD cohort, identified through routine opportunistic testing, with a 6-year follow-up (≈ 13,000 patient-years). METHODS: A cohort had previously been identified with CKD-sustained reduced eGFR over at least 3 months and case note review. Six-year (13,339 patient-years) follow-up for renal replacement therapy (RRT) initiation and death was achieved through data linkage. Age- and sex-specific mortality rates were compared to the general population. RESULTS: Of 3414 individuals (most Stage 3b-5), median age 78.6 years, followed for 13 339 patient-years, 170 (5%) initiated RRT and 2024 (59%) died without initiating RRT. RRT initiation rates decreased with age from 14.33 to 0.65 per 100 patient-years among those aged 15-25 and 75-85 years at baseline but the actual numbers initiating RRT increased from 6 to 34, respectively. RRT initiation rates were lower for female sex, absence of macroalbuminuria and less advanced CKD stage. Mortality rates increased with age from 2 to 34 per 100 patient-years for those aged 15-45 and > 85 years at baseline, an excess of 2 and 17 per 100 patient-years over that of the general population, respectively. However, the increase in relative risk was 19-fold for those aged 15-45 years and just 2-fold in those > 85 years. These data have been converted into simple tools for considering individual patients' risk and informing service planning. CONCLUSIONS: The contrast between relative and absolute risk for both RRT initiation and mortality by age group illustrates the difficulties for planning services. The challenge that now faces clinicians is how to appropriately identify which elderly patients with CKD are at high risk of poor outcome.

Global variation in renal replacement therapy for end-stage renal disease.

BACKGROUND: Incidence rates of renal replacement therapy (RRT) for end-stage renal disease vary considerably worldwide. This study examines the independent association between the general population, health care system and renal service characteristics and RRT incidence rates. METHODS: RRT incidence data (2003-2005) were obtained from renal registries; general population age and health and macroeconomic indices were collected from secondary sources. Renal service organization and resource data were obtained through interviews and questionnaires. Linear regression models were built to establish the factors independently associated with RRT incidence, stratified by the Human Development Index where required. False discovery rate (FDR) correction was adjusted for multiple testing. RESULTS: Across the 46 countries (population 1.25 billion), RRT incidence rates ranged from 12 to 455 (median 130) per million population. Gross domestic product (GDP) per capita [incidence rate ratio (IRR): 1.02 per $1000 increase, P(FDR) = 0.047], percentage of GDP spent on health care (IRR: 1.11 per % increase, P(FDR) = 0.006) and dialysis facility reimbursement rate relative to GDP (IRR: 0.76 per GDP per capita-sized increase in reimbursement rate, P(FDR) = 0.007) were independently associated with RRT incidence. In more developed countries, the private for-profit share of haemodialysis facilities was also associated with higher incidence (IRR: 1.009 per % increase, P(FDR) = 0.003). CONCLUSIONS: Macroeconomic and renal service factors are more often associated with RRT incidence rates than measured demographic or general population health status factors.

Systematic review of antimicrobials for the prevention of haemodialysis catheter-related infections.

BACKGROUND: Almost 30% of chronic haemodialysis (HD) patients are dependent on central venous catheters (CVCs) for their vascular access, and catheter-related bacteraemia (CRB) is the major reason for catheter loss and has been associated with substantial morbidity, including meta-static infections. This systematic review evaluates the benefits and harms of antimicrobial interventions for the prevention of catheter-related infections (CRIs). METHODS: MEDLINE (1950-May 2009), EMBASE (1980-May 2009) CENTRAL (up to May 2009) and bibliographies of retrieved articles were searched for relevant RCTs. Analysis was by a random effects model and results expressed as rate ratio, relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI). RESULTS: A total of 29 trials with 2886 patients and 3005 catheters were included. Antimicrobial catheter locks (AMLs) significantly reduced the rates of CRBs (rate ratio, 0.33, 95% CI 0.24-0.45) and exit-site infections (ESIs) (rate ratio 0.67, 95% CI 0.47-0.96). Exit-site antimicrobial application also significantly reduced the rates of CRBs (rate ratio 0.21, 95% CI 0.12-0.36) and ESIs (rate ratio 0.22, 95% CI 0.10-0.47). Antimicrobial coating of HD catheters and the use of peri-operative antimicrobials did not result in significant reduction in rates of CRBs and ESIs. CONCLUSION: The use of AMLs and exit-site antimicrobials are useful measures in the reduction of CRIs, whereas antimicrobial impregnated catheters and peri-operative systemic antimicrobial administration have not been found to be beneficial. Further head-to-head trials of various AMLs and exit-site antimicrobials are needed to know about their comparative clinical efficacy.

Comparison of hemodialysis, hemofiltration, and acetate-free biofiltration for ESRD: systematic review.

BACKGROUND: We performed a systematic review of randomized controlled trials (RCTs) comparing hemodialysis (HD), hemofiltration (HF), hemodiafiltration (HDF), and acetate-free biofiltration (AFB) in the treatment of patients with end-stage renal disease to assess their clinical effectiveness. METHODS: The Cochrane CENTRAL Registry, MEDLINE, EMBASE, CINAHL, the American College of Physicians Database, Database of Abstracts of Reviews of Effectiveness, and reference lists were searched for randomized trials of HF, HDF, and AFB compared with HD; HDF compared with AFB; and HF compared with HDF. Two reviewers extracted data for all-cause mortality; hypotension, headache, nausea, vomiting, and any other adverse symptoms; quality of life (QoL); hospitalization; dialysis adequacy; and end-of-treatment beta 2 -microglobulin levels. Analysis was by means of a random-effects model, and results are expressed as relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CIs). RESULTS: Eighteen eligible trials (588 patients) were identified. HDF was associated with significantly greater mortality risk than HD (4 trials, 326 patients; RR, 3.52; 95% CI, 1.37 to 9.47). Risk for mortality was not different among the other comparisons. Risks for hypotension episodes and dialysis-related symptoms were not significantly different with HD, HF, HDF, and AFB (18 trials, 583 patients). QoL, assessed by using an unvalidated scoring tool, appeared to be significantly improved in patients on HDF therapy than those on HD therapy (1 trial, 67 patients; WMD, 0.6; 95% CI, 0.3 to 0.9), but this was not evident when validated QoL assessment tools were used. Use of AFB compared with HDF was not associated with a significant difference in risk for hospitalization (1 trial, 11 patients; WMD, -0.45; 95% CI, -1.42 to 0.52). HDF in comparison to HD did not reduce the risk for carpal tunnel syndrome (1 trial, 67 patients; RR, 2.04; 95% CI, 0.59 to 7.00). Kt/V was significantly different with HDF compared with HD (3 trials, 124 patients; WMD, 0.14; 95% CI, 0.05 to 0.22). No other substantial data for these interventions and their impact on major patient-centered outcomes were available. CONCLUSION: The trials assessed were not powered adequately and had suboptimal method quality. It is not possible on the basis of effectiveness to prefer one extracorporeal renal replacement therapy modality to the other for end-stage kidney disease because significant differences in clinically important outcomes have not been shown by available published RCTs.

Exploring the association between macroeconomic indicators and dialysis mortality.

BACKGROUND AND OBJECTIVES: Mortality on dialysis varies greatly worldwide, with patient-level factors explaining only a small part of this variation. The aim of this study was to examine the association of national-level macroeconomic indicators with the mortality of incident dialysis populations and explore potential explanations through renal service indicators, incidence of dialysis, and characteristics of the dialysis population. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Aggregated unadjusted survival probabilities were obtained from 22 renal registries worldwide for patients starting dialysis in 2003-2005. General population age and health, macroeconomic indices, and renal service organization data were collected from secondary sources and questionnaires. Linear modeling with log-log transformation of the outcome variable was applied to establish factors associated with survival on dialysis. RESULTS: Two-year survival on dialysis ranged from 62.3% in Iceland to 89.8% in Romania. A higher gross domestic product per capita (hazard ratio=1.02 per 1000 US dollar increase), a higher percentage of gross domestic product spent on healthcare (1.10 per percent increase), and a higher intrinsic mortality of the dialysis population (i.e., general population-derived mortality risk of the dialysis population in that country standardized for age and sex; hazard ratio=1.04 per death per 10,000 person years) were associated with a higher mortality of the dialysis population. The incidence of dialysis and renal service indicators were not associated with mortality on dialysis. CONCLUSIONS: Macroeconomic factors and the intrinsic mortality of the dialysis population are associated with international differences in the mortality on dialysis. Renal service organizational factors and incidence of dialysis seem less important.

The EVEREST study: an international collaboration.

Rates of initiation of renal replacement therapy (RRT), use of home modalities of treatment and patient outcomes vary considerably between countries. This paper reports the methods and baseline characteristics of countries participating in the EVEREST study (n = 46), a global collaboration examining the association between medical and non-medical factors and RRT incidence, modality mix and survival. Numbers of incident and prevalent patients were collected for current (2003-05) and historic (1983-85, 1988-90, 1993-95 and 1998-2000) periods stratified, where available, by age, gender, treatment modality and cause of end stage renal disease (diabetic versus non-diabetic). General population age and health indicators and national-level macroeconomic data were collected from secondary data sources. National experts provided primary data on renal service funding, resources and organization. The median (inter quartile range) RRT incidence per million of the population (pmp) was 130 pmp (102-167 pmp). The general population life expectancy at 60 was 22.1 years (19.7-23.1 years) and 6.9% had diabetes mellitus (5.4-9.0%). Healthcare spending as a percentage of gross domestic product was 8.1% (5.6-9.3%). Countries averaged nine dialysis facilities pmp (4-12 pmp), with 69.0% (43.9-99.0%) owned by the public or private not-for-profit sector. The number of nephrologists ranged from 0.5 to 48 pmp (median 12 pmp). The heterogeneity of EVEREST countries will enable modelling to examine the independent association between medical and non-medical factors on RRT epidemiology.

Automated vs continuous ambulatory peritoneal dialysis: a systematic review of randomized controlled trials.

BACKGROUND: A systematic review of randomized controlled trials (RCTs) comparing continuous ambulatory peritoneal dialysis (CAPD) with all forms of automated peritoneal dialysis (APD) was performed to assess their comparative clinical effectiveness. METHODS: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL, were searched for relevant RCTs. Analysis was by a random effects model and results expressed as relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI). RESULTS: Three trials (139 patients) were identified. APD when compared to CAPD was found to have significantly lower peritonitis rates (two trials, 107 patients, rate ratio 0.54, 95% CI 0.35-0.83) and hospitalization rates (one trial, 82 patients, rate ratio 0.60, 95% CI 0.39-0.93) but not exit-site infection rates (two trials, 107 patients, rate ratio 1.00, 95% CI 0.56-1.76). However no differences were detected between APD and CAPD in respect to risk of mortality (RR 1.49, 95% CI 0.51-4.37), peritonitis (RR 0.75, 95% CI 0.50-1.11), switching from the original peritoneal dialysis (PD) modality to a different dialysis modality including an alternative form of PD (RR 0.50, 95% CI 0.25-1.02), PD catheter removal (RR 0.64, 95% CI 0.27-1.48) and hospital admissions (RR 0.96, 95% CI 0.43-2.17). Patients on APD were found to have significantly more time for work, family and social activities. CONCLUSIONS: APD appears to be more beneficial than CAPD, in terms of reducing peritonitis rates and with respect to certain social issues that impact on patients' quality of life. Further, adequately powered trials are required to confirm the benefits for APD found in this review and detect differences with respect to other clinically important outcomes that may have been missed by the trials included in this review due to their small size and short follow-up periods.

A prospective national study of acute renal failure treated with RRT: incidence, aetiology and outcomes.

BACKGROUND: Acute renal failure (ARF) is a diverse condition with no standardized definition and is managed in several sub-specialty areas within hospitals. Its incidence and aetiology are unknown and studies show a wide range of incidences. ARF is becoming more common as the population ages leading to the hypothesis that the incidence is much higher than previous estimates. METHODS: This prospective population study investigated the incidence, aetiology and outcomes of ARF based on a standardized classification of ARF treated by renal replacement therapy (RRT) in all sub-specialty areas within hospitals where such treatment takes place. Data were collected prospectively on all patients starting RRT for ARF within three 12-week periods in 2002. RESULTS: Two hundred eighty-six adults per million population (pmp) per year received RRT for ARF. The incidence increased with age and pre-existing comorbid illness. Two hundred twelve adults pmp per year had no evidence of pre-existing chronic kidney disease (CKD) and the remainder had acute on CKD. The median age was 67 years. Fifty-one percent of the patients received their first RRT treatment in a critical care setting. Sepsis was the most common aetiological insult contributing to ARF in 48% of the patients. Mortality was high with 48% dying within 90 days of starting RRT. Age, comorbidity, sepsis and recent surgery were independent risk factors for death in those with no pre-existing CKD. DISCUSSION: This is the first national study to describe ARF treated with RRT in all hospital locations. The hypothesis that ARF occurs more frequently than previously thought has been confirmed. This study provides data upon which to base effective decision making for prevention, patient care and resource planning for patients with ARF.

End-stage renal disease in Scotland: outcomes and standards of care.

BACKGROUND: The number of patients starting renal replacement therapy (RRT) for end-stage renal disease (ESRD) in the United Kingdom rises annually. Patients are increasingly elderly with a greater prevalence of comorbid illness. Unadjusted survival, from the time of starting RRT, is not improving. The United Kingdom Renal Association has published recommended standards of treatment, which all United Kingdom nephrologists strive to attain. This study was devised to define the impact of attaining recommended treatment standards, adjusting for patient age and comorbid illnesses, upon survival on RRT in the United Kingdom population. METHODS: A prospective, registry based, observational study of all patients starting RRT in Scotland over a 1-year period, followed for the first 2 years of RRT. RESULTS: Of the 523 patients who were studied, 217 (41.5%) had died by 2 years of follow-up, 32% excluding deaths within the first 90 days. Age, comorbidity, weight when starting RRT, and attaining the recommended standards for albumin and hemoglobin had a significant impact upon survival. CONCLUSION: This study has emphasized the very high mortality of patients starting RRT in Scotland. By paying close attention to the attainment of recommended standards of care for patients with ESRD, it may be possible to improve upon current mortality figures. The monitoring of such success is only possible if correction is made for age and comorbidity.

Early referral and planned initiation of dialysis: what impact on quality of life?

BACKGROUND: Early patient referral correlates with improved patient survival on dialysis. We examine whether early referral and a planned first dialysis affect quality of life (QoL). METHODS: All patients commencing dialysis in nine centres in seven European countries between 1 July 1998 and 31 October 1999 were recruited. DEFINITIONS: early referral=followed by a nephrologist >1 month before first dialysis (<1 month=late referral); planned=early referral and previous serum creatinine >300 micro mol/l and non-urgent first dialysis (early referral and no creatinine >300 micro mol/l or urgent first dialysis=unplanned). QoL was measured at 8 weeks using a visual analogue scale (VAS) and Short Form 36 (SF-36). RESULTS: VAS was significantly higher in early referral patients [mean (SD) 58.4 (20) vs 50.4 (19), P=0.005], particularly if the first dialysis was planned [60.7 (20) vs 54.2 (20), P=0.03]. Planned patients also had higher SF-36 mental summary scores [45.4 (12) vs 39.7 (11), P=0.003], role emotional scores [58.0 (43) vs 30.9 (38), P=0.003], and mental health scores [63.7 (24) vs 54.6 (22), P=0.01] than unplanned patients. Adjusting for centre and other confounding variables showed that having a planned first dialysis had an independent effect on QoL (VAS, and the SF-36's mental summary score, physical functioning, role physical, general health, role emotional and mental health). Early referral had no independent effect on QoL. Socio-economic status had an important positive effect on physical QoL. CONCLUSIONS: While the effect of early referral to a nephrologist on QoL appeared centre dependent, a smooth transition onto dialysis was associated with significantly better early QoL, independent of other variables.