The aim of this study was to investigate 28-day mortality after COVID-19 diagnosis in the European kidney replacement therapy population. In addition, we determined the role of patient ...characteristics, treatment factors, and country on mortality risk with the use of ERA-EDTA Registry data on patients receiving kidney replacement therapy in Europe from February 1, 2020, to April 30, 2020. Additional data on all patients with a diagnosis of COVID-19 were collected from 7 European countries encompassing 4298 patients. COVID-19–attributable mortality was calculated using propensity score–matched historic control data and after 28 days of follow-up was 20.0% (95% confidence interval 18.7%–21.4%) in 3285 patients receiving dialysis and 19.9% (17.5%–22.5%) in 1013 recipients of a transplant. We identified differences in COVID-19 mortality across countries, and an increased mortality risk in older patients receiving kidney replacement therapy and male patients receiving dialysis. In recipients of kidney transplants ≥75 years of age, 44.3% (35.7%–53.9%) did not survive COVID-19. Mortality risk was 1.28 (1.02–1.60) times higher in transplant recipients compared with matched dialysis patients. Thus, the pandemic has had a substantial effect on mortality in patients receiving kidney replacement therapy, a highly vulnerable population due to underlying chronic kidney disease and a high prevalence of multimorbidity.
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ABSTRACT
In this article we introduce the concept of inverse probability of treatment weighting (IPTW) and describe how this method can be applied to adjust for measured confounding in observational ...research, illustrated by a clinical example from nephrology. IPTW involves two main steps. First, the probability—or propensity—of being exposed to the risk factor or intervention of interest is calculated, given an individual’s characteristics (i.e. propensity score). Second, weights are calculated as the inverse of the propensity score. The application of these weights to the study population creates a pseudopopulation in which confounders are equally distributed across exposed and unexposed groups. We also elaborate on how weighting can be applied in longitudinal studies to deal with informative censoring and time-dependent confounding in the setting of treatment-confounder feedback.
Although overall donation and transplantation activity is higher in Europe than on other continents, differences between European countries in almost every aspect of transplantation activity (for ...example, in the number of transplantations, the number of people with a functioning graft, in rates of living versus deceased donation, and in the use of expanded criteria donors) suggest that there is ample room for improvement. Herein we review the policy and clinical measures that should be considered to increase access to transplantation and improve post-transplantation outcomes. This Roadmap, generated by a group of major European stakeholders collaborating within a Thematic Network, presents an outline of the challenges to increasing transplantation rates and proposes 12 key areas along with specific measures that should be considered to promote transplantation. This framework can be adopted by countries and institutions that are interested in advancing transplantation, both within and outside the European Union. Within this framework, a priority ranking of initiatives is suggested that could serve as the basis for a new European Union Action Plan on Organ Donation and Transplantation.
CKD prevalence estimation is central to CKD management and prevention planning at the population level. This study estimated CKD prevalence in the European adult general population and investigated ...international variation in CKD prevalence by age, sex, and presence of diabetes, hypertension, and obesity. We collected data from 19 general-population studies from 13 European countries. CKD stages 1-5 was defined as eGFR<60 ml/min per 1.73 m(2), as calculated by the CKD-Epidemiology Collaboration equation, or albuminuria >30 mg/g, and CKD stages 3-5 was defined as eGFR<60 ml/min per 1.73 m(2) CKD prevalence was age- and sex-standardized to the population of the 27 Member States of the European Union (EU27). We found considerable differences in both CKD stages 1-5 and CKD stages 3-5 prevalence across European study populations. The adjusted CKD stages 1-5 prevalence varied between 3.31% (95% confidence interval 95% CI, 3.30% to 3.33%) in Norway and 17.3% (95% CI, 16.5% to 18.1%) in northeast Germany. The adjusted CKD stages 3-5 prevalence varied between 1.0% (95% CI, 0.7% to 1.3%) in central Italy and 5.9% (95% CI, 5.2% to 6.6%) in northeast Germany. The variation in CKD prevalence stratified by diabetes, hypertension, and obesity status followed the same pattern as the overall prevalence. In conclusion, this large-scale attempt to carefully characterize CKD prevalence in Europe identified substantial variation in CKD prevalence that appears to be due to factors other than the prevalence of diabetes, hypertension, and obesity.
Studies in cardiology often record the time to multiple disease events such as death, myocardial infarction, or hospitalization. Competing risks methods allow for the analysis of the time to the ...first observed event and the type of the first event. They are also relevant if the time to a specific event is of primary interest but competing events may preclude its occurrence or greatly alter the chances to observe it. We give a non-technical overview of competing risks concepts for descriptive and regression analyses. For descriptive statistics, the cumulative incidence function is the most important tool. For regression modelling, we introduce regression models for the cumulative incidence function and the cause-specific hazard function, respectively. We stress the importance of choosing statistical methods that are appropriate if competing risks are present. We also clarify the role of competing risks for the analysis of composite endpoints.
The most commonly used methods to investigate risk factors associated with renal function trajectory over time include linear regression on individual glomerular filtration rate (GFR) slopes, linear ...mixed models and generalized estimating equations (GEEs). The objective of this study was to explain the principles of these three methods and to discuss their advantages and limitations in particular when renal function trajectories are not completely observable due to dropout.
We generated data from a hypothetical cohort of 200 patients with chronic kidney disease at inclusion and seven subsequent annual measurements of GFR. The data were generated such that both baseline level and slope of GFR over time were associated with baseline albuminuria status. In a second version of the dataset, we assumed that patients systematically dropped out after a GFR measurement of <15 mL/min/1.73 m(2). Each dataset was analysed with the three methods.
The estimated effects of baseline albuminuria status on GFR slope were similar among the three methods when no patient dropped out. When 32.7% dropped out, standard GEE provided biased estimates of the mean GFR slope in normo-, micro- and macroalbuminuric patients. Linear regression on individual slopes and linear mixed models provided slope estimates of the same magnitude, likely because most patients had at least three GFR measurements. However, the linear mixed model was the only method to provide effect estimates on both slope and baseline level of GFR unaffected by dropout.
This study illustrates that the linear mixed model is the preferred method to investigate risk factors associated with renal function trajectories in studies, where patients may dropout during the study period because of initiation of renal replacement therapy.
The aim of this study is to present average annual healthcare costs for Dutch renal replacement therapy (RRT) patients for 7 treatment modalities.
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).
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).
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.
Background The proportion of patients with advanced chronic kidney disease (CKD) initiating dialysis therapy at a higher glomerular filtration rate (GFR) has increased during the past decade. Recent ...data suggest that higher GFR may be associated with increased mortality. Study Design A meta-analysis of cohort studies and trials. Setting & Population Patients with advanced CKD. Selection Criteria for Studies We performed a systematic literature search in MEDLINE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov , American Society of Nephrology abstracts, and bibliographies of retrieved articles to identify studies reporting on GFR at dialysis therapy initiation and mortality. Predictor Estimated or calculated GFR at dialysis therapy initiation. Outcome Pooled adjusted hazard ratio (HR) of continuous GFR for all-cause mortality. Results 16 cohort studies and 1 randomized controlled trial were identified (n = 1,081,116). By meta-analysis restricted to 15 cohorts (n = 1,079,917), higher GFR at dialysis therapy initiation was associated with a higher pooled adjusted HR for all-cause mortality (1.04; 95% CI, 1.03-1.05; P < 0.001). However, there was significant heterogeneity ( I2 = 97%; P < 0.001). The association persisted among the 9 cohorts that adjusted analytically for nutritional covariates (HR, 1.03; 95% CI, 1.02-1.04; P < 0.001; residual I2 = 97%). The highest mortality risk was observed in hemodialysis cohorts (HR, 1.05; 95% CI, 1.02-1.08; P < 0.001), whereas there was no association between GFR and mortality in peritoneal dialysis cohorts (HR, 1.04; 95% CI, 0.99-1.08, P = 0.1; residual I2 = 98%). Finally, higher GFR was associated with a lower mortality risk in cohorts that calculated GFR (HR, 0.80; 95% CI, 0.71-0.91; P = 0.003), contrasting with a higher mortality risk in cohorts that estimated GFR (HR, 1.04; 95% CI, 1.03-1.05; P < 0.001; residual I2 = 97%). Limitations Paucity of randomized controlled trials, different methods for determining GFR, and substantial heterogeneity. Conclusions Higher estimated rather than calculated GFR at dialysis therapy initiation is associated with a higher mortality risk in patients with advanced CKD, independent of nutritional status. Although there was substantial heterogeneity of effect size estimates across studies, this observation requires further study.
Large international differences exist in access to renal replacement therapy (RRT) modalities and comprehensive conservative management (CCM) for patients with end-stage kidney disease (ESKD), ...suggesting that some patients are not receiving the most appropriate treatment. Previous studies mainly focused on barriers reported by patients or medical barriers (e.g. comorbidities) reported by nephrologists. An overview of the non-medical barriers reported by nephrologists when providing the most appropriate form of RRT (other than conventional in-centre haemodialysis) or CCM is lacking.
We searched in EMBASE and PubMed for original articles with a cross-sectional design (surveys, interviews or focus groups) published between January 2010 and September 2018. We included studies in which nephrologists reported barriers when providing RRT or CCM to adult patients with ESKD. We used the barriers and facilitators survey by Peters et al. Ruimte Voor Verandering? Knelpunten en Mogelijkheden Voor Verbeteringen in de Patiëntenzorg. Nijmegen: Afdeling Kwaliteit van zorg (WOK), 2003 as preliminary framework to create our own model and performed meta-ethnographic analysis of non-medical barriers in text, tables and figures.
Of the 5973 articles screened, 16 articles were included using surveys (n = 10), interviews (n = 5) and focus groups (n = 1). We categorized the barriers into three levels: patient level (e.g. attitude, role perception, motivation, knowledge and socio-cultural background), level of the healthcare professional (e.g. fears and concerns, working style, communication skills) and level of the healthcare system (e.g. financial barriers, supportive staff and practice organization).
Our systematic review has identified a number of modifiable, non-medical barriers that could be targeted by, for example, education and optimizing financing structure to improve access to RRT modalities and CCM.
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