Recovery of Renal Function after One-Year of Dialysis Treatment: Case Report and Registry Data

Objective. Uncertainty has arisen as to whether renal function can be recovered from after long-term regular dialysis treatment. We therefore conducted an analysis and scrutinized one patient report. Material and Methods. Swedish registry of patients with kidney disease and one patient case. Results. 39 patients (0.2%) from the Swedish registry comprising 17590 patients who commenced RRT (renal replacement therapy) between 1991 and 2008 had recovered from renal function after more than 365 days of regular dialysis treatment. The most common diagnosis was renovascular disease with hypertension but a large group had uremia of unknown cause. HUS, cortical/tubular necrosis, and autoimmune diseases were also found. The mean treatment time before withdrawal was 2 years. Conclusions. A small number of patients recover after a long period of regular dialysis treatment. One could discuss whether it is difficult to identify patients who have recovered while undergoing regular dialysis treatment. Regular monitoring of renal function may be important

A prospective observational study of iron isomaltoside in haemodialysis patients with chronic kidney disease treated for iron deficiency (DINO).

Iron deficiency is frequent in haemodialysis (HD) patients with chronic kidney disease (CKD), and intravenous iron is an established therapy for these patients. This study assessed treatment routine, effectiveness, and safety of iron isomaltoside (IIM) 5% (Diafer®) in a HD cohort.This article is freely available via Open Access. Click on the link to the publisher's site to access the full-text

Serum potassium and adverse outcomes across the range of kidney function: a CKD Prognosis Consortium meta-analysis.

Aims: Both hypo- and hyperkalaemia can have immediate deleterious physiological effects, and less is known about long-term risks. The objective was to determine the risks of all-cause mortality, cardiovascular mortality, and end-stage renal disease associated with potassium levels across the range of kidney function and evaluate for consistency across cohorts in a global consortium. Methods and results: We performed an individual-level data meta-analysis of 27 international cohorts [10 general population, 7 high cardiovascular risk, and 10 chronic kidney disease (CKD)] in the CKD Prognosis Consortium. We used Cox regression followed by random-effects meta-analysis to assess the relationship between baseline potassium and adverse outcomes, adjusted for demographic and clinical characteristics, overall and across strata of estimated glomerular filtration rate (eGFR) and albuminuria. We included 1 217 986 participants followed up for a mean of 6.9 years. The average age was 55 ± 16 years, average eGFR was 83 ± 23 mL/min/1.73 m2, and 17% had moderate- to-severe increased albuminuria levels. The mean baseline potassium was 4.2 ± 0.4 mmol/L. The risk of serum potassium of >5.5 mmol/L was related to lower eGFR and higher albuminuria. The risk relationship between potassium levels and adverse outcomes was U-shaped, with the lowest risk at serum potassium of 4-4.5 mmol/L. Compared with a reference of 4.2 mmol/L, the adjusted hazard ratio for all-cause mortality was 1.22 [95% confidence interval (CI) 1.15-1.29] at 5.5 mmol/L and 1.49 (95% CI 1.26-1.76) at 3.0 mmol/L. Risks were similar by eGFR, albuminuria, renin-angiotensin-aldosterone system inhibitor use, and across cohorts. Conclusions: Outpatient potassium levels both above and below the normal range are consistently associated with adverse outcomes, with similar risk relationships across eGFR and albuminuria

Cost-effectiveness analysis of treatment with epoietin-alpha for patients with anaemia due to renal failure: The case of Sweden.

Abstract OBJECTIVE: Anaemia is a common complication of renal failure. It can be treated with erythropoietin (EPO) administration, red blood cell transfusion (RBCT), or a combination of both. EPO has been registered for the treatment of renal anaemia in Sweden since the beginning of the 1990s, and is the primary treatment regimen for anaemia related to renal failure. The objective of this study was to carry out a cost-effectiveness analysis from a provider perspective of a treatment strategy comprising EPO and complementary RBCT compared to the traditional treatment of RBCT alone for patients with anaemia associated with renal failure in Sweden. MATERIAL AND METHODS: Incremental costs and quality-adjusted life-years (QALYs) associated with EPO (epoietin-alpha) treatment compared to the traditional therapy of RBCT were estimated. The QALY gains were estimated using a modified version of a Markov model, which is used by the UK National Institute of Clinical Excellence in their evaluations of EPO treatment in the UK. Swedish treatment practice (i.e. EPO doses and iron supplementation), patient characteristics and unit costs were used throughout the study. RESULTS: The estimated cost per QALY gained from administration of EPO to renal patients falls within the range acceptable in Sweden for both haemodialysis and peritoneal dialysis patients. CONCLUSIONS: EPO administration to renal patients is much more costly in Sweden than in the UK, primarily due to the higher dosage of EPO and iron supplementation used in Sweden. However, Swedish patients reach higher haemoglobin levels, and thereby achieve higher QALY gains, compared to patients in the UK

Renal failure occurs in chronic lithium treatment but is uncommon.

We sought to establish the prevalence of lithium-induced end-stage renal disease in two regions of Sweden with 2.7 million inhabitants corresponding to about 30% of the Swedish population. Eighteen patients with lithium-induced end-stage renal disease were identified among the 3369 patients in the general lithium-treated population, representing a sixfold increase in prevalence compared with the general population for renal replacement therapy. All lithium-treated patients were older than 46 years at end-stage renal disease with a mean lithium treatment time of 23 years with ten patients having discontinued lithium treatment an average of 10 years before the start of renal replacement therapy. The prevalence of chronic kidney disease (defined as plasma creatinine over 150 mumol/l) in the general lithium-treated population was about 1.2% (excluding patients on renal replacement therapy). Compared with lithium-treated patients without renal failure, those with chronic kidney disease were older and most were men but, as groups, their mean serum lithium levels and psychiatric diagnoses did not differ. We found that end-stage renal disease is an uncommon but not rare consequence of long-term lithium treatment and is more prevalent than previously thought. Time on lithium was the only identified risk factor in this study, suggesting that regular monitoring of renal function in these patients is mandatory.Kidney International advance online publication, 25 November 2009; doi:10.1038/ki.2009.433

Trial emulation and survival analysis for disease incidence registers : A case study on the causal effect of pre-emptive kidney transplantation

When drawing causal inference from observed data, failure time outcomes present additional challenges of censoring often combined with other missing data patterns. In this article, we follow incident cases of end-stage renal disease to examine the effect on all-cause mortality of starting treatment with transplant, so-called pre-emptive kidney transplantation, vs starting with dialysis possibly followed by delayed transplantation. The question is relatively simple: which start-off treatment is expected to bring the best survival for a target population? To address it, we emulate a target trial drawing on the long term Swedish Renal Registry, where a growing common set of baseline covariates was measured nationwide. Several lessons are learned which pertain to long term disease registers more generally. With characteristics of cases and versions of treatment evolving over time, informative censoring is already introduced in unadjusted Kaplan-Meier curves. This leads to misrepresented survival chances in observed treatment groups. The resulting biased treatment association may be aggravated upon implementing IPW for treatment. Aware of additional challenges, we further recall how similar studies to date have selected patients into treatment groups based on events occurring post treatment initiation. Our study reveals the dramatic impact of resulting immortal time bias combined with other typical features of long-term incident disease registers, including missing covariates during the early phases of the register. We discuss feasible ways of accommodating these features when targeting relevant estimands, and demonstrate how more than one causal question can be answered relying on the no unmeasured baseline confounders assumption

Causal inference in survival analysis under deterministic missingness of confounders in register data

Long-term register data offer unique opportunities to explore causal effects of treatments on time-to-event outcomes, in well-characterized populations with minimum loss of follow-up. However, the structure of the data may pose methodological challenges. Motivated by the Swedish Renal Registry and estimation of survival differences for renal replacement therapies, we focus on the particular case when an important confounder is not recorded in the early period of the register, so that the entry date to the register deterministically predicts confounder missingness. In addition, an evolving composition of the treatment arms populations, and suspected improved survival outcomes in later periods lead to informative administrative censoring, unless the entry date is appropriately accounted for. We investigate different consequences of these issues on causal effect estimation following multiple imputation of the missing covariate data. We analyse the performance of different combinations of imputation models and estimation methods for the population average survival. We further evaluate the sensitivity of our results to the nature of censoring and misspecification of fitted models. We find that an imputation model including the cumulative baseline hazard, event indicator, covariates and interactions between the cumulative baseline hazard and covariates, followed by regression standardization, leads to the best estimation results overall, in simulations. Standardization has two advantages over inverse probability of treatment weighting here: it can directly account for the informative censoring by including the entry date as a covariate in the outcome model, and allows for straightforward variance computation using readily available software

End-stage renal disease associated with prophylactic lithium treatment.

The primary aim of this study was to estimate the prevalence of lithium associated end-stage renal disease (ESRD) and to compare the relative risk of ESRD in lithium users versus non-lithium users. Second, the role of lithium in the pathogenesis of ESRD was evaluated. We used the Swedish Renal Registry to search for lithium-treated patients with ESRD among 2644 patients with chronic renal replacement therapy (RRT)-either dialysis or transplantation, within two defined geographical areas in Sweden with 2.8 million inhabitants. The prevalence date was December 31, 2010. We found 30 ESRD patients with a history of lithium treatment. ESRD with RRT was significantly more prevalent among lithium users than among non-lithium users (p<0.001). The prevalence of ESRD with RRT in the lithium user population was 15.0‰ (95% CI 9.7-20.3), and close to two percent of the RRT population were lithium users. The relative risk of ESRD with RRT in the lithium user population compared with the general population was 7.8 (95% CI 5.4-11.1). Out of those 30 patients, lithium use was classified, based on chart reviews, as being the sole (n=14) or main (n=10) cause of ESRD in 24 cases. Their mean age at the start of RRT was 66 years (46-82), their mean time on lithium 27 years (12-39), and 22 of them had been on lithium for 15 years or more. We conclude that lithium-associated ESRD is an uncommon but not rare complication of lithium treatment

End-stage renal disease and low level exposure to lead, cadmium and mercury : a population-based, prospective nested case-referent study in Sweden

BACKGROUND: Cadmium (Cd), lead (Pb), and mercury (Hg) cause toxicological renal effects, but the clinical relevance at low-level exposures in general populations is unclear. The objective of this study is to assess the risk of developing end-stage renal disease in relation to Cd, Pb, and Hg exposure. METHODS: A total of 118 cases who later in life developed end-stage renal disease, and 378 matched (sex, age, area, and time of blood sampling) referents were identified among participants in two population-based prospective cohorts (130,000 individuals). Cd, Pb, and Hg concentrations were determined in prospectively collected samples. RESULTS: Erythrocyte lead was associated with an increased risk of developing end-stage renal disease (mean in cases 76 μg/L; odds ratio (OR) 1.54 for an interquartile range increase, 95% confidence interval (CI) 1.18-2.00), while erythrocyte mercury was negatively associated (2.4 μg/L; OR 0.75 for an interquartile range increase, CI 0.56-0.99). For erythrocyte cadmium, the OR of developing end-stage renal disease was 1.15 for an interquartile range increase (CI 0.99-1.34; mean Ery-Cd among cases: 1.3 μg/L). The associations for erythrocyte lead and erythrocyte mercury, but not for erythrocyte cadmium, remained after adjusting for the other two metals, smoking, BMI, diabetes, and hypertension. Gender-specific analyses showed that men carried almost all of the erythrocyte lead and erythrocyte cadmium associated risks. CONCLUSIONS: Erythrocyte lead is associated with end-stage renal disease but further studies are needed to evaluate causality. Gender-specific analyses suggest potential differences in susceptibility or in exposure biomarker reliability