Survival of patients treated with extended-hours haemodialysis in Europe: an analysis of the ERA-EDTA Registry

Abstract

Background Previous US studies have indicated that haemodialysis with ≥6-h sessions [extended-hours haemodialysis (EHD)] may improve patient survival. However, patient characteristics and treatment practices vary between the USA and Europe. We therefore investigated the effect of EHD three times weekly on survival compared with conventional haemodialysis (CHD) among European patients. Methods We included patients who were treated with haemodialysis between 2010 and 2017 from eight countries providing data to the European Renal Association–European Dialysis and Transplant Association Registry. Haemodialysis session duration and frequency were recorded once every year or at every change of haemodialysis prescription and were categorized into three groups: CHD (three times weekly, 3.5–4 h/treatment), EHD (three times weekly, ≥6 h/treatment) or other. In the primary analyses we attributed death to the treatment at the time of death and in secondary analyses to EHD if ever initiated. We compared mortality risk for EHD to CHD with causal inference from marginal structural models, using Cox proportional hazards models weighted for the inverse probability of treatment and censoring and adjusted for potential confounders. Results From a total of 142 460 patients, 1338 patients were ever treated with EHD (three times, 7.1 ± 0.8 h/week) and 89 819 patients were treated exclusively with CHD (three times, 3.9 ± 0.2 h/week). Crude mortality rates were 6.0 and 13.5/100 person-years. In the primary analyses, patients treated with EHD had an adjusted hazard ratio (HR) of 0.73 [95% confidence interval (CI) 0.62–0.85] compared with patients treated with CHD. When we attributed all deaths to EHD after initiation, the HR for EHD was comparable to the primary analyses [HR 0.80 (95% CI 0.71–0.90)]. Conclusions EHD is associated with better survival in European patients treated with haemodialysis three times weekly.

Data from the ERA-EDTA Registry were examined for trends in excess mortality in European adults on kidney replacement therapy

“…[16][17][18] Work by Tentori et al showed that over time most European countries included in the Dialysis Outcomes and Practice Patterns Study had a longer HD session time, which was associated with a lower mortality risk. 19,20 In addition, a decrease in interdialytic weight gain, as shown from phase 2 to 5 in the Dialysis Outcomes and Practice Patterns Study, may have led to a reduction in intradialytic hypotensive episodes, thereby contributing to the enhanced survival. 21 The lack of improvement of the excess mortality risk in PD patients may be due to the lower excess mortality rates, leaving less room for improvement over time.…”

No evidence of a legacy effect on survival following randomization to extended hours dialysis in the ACTIVE Dialysis trial

“…3,4,21,22 This suggests that our cohort was representative of patients typically offered more intensive dialysis schedules, who are known to have better prognostic characteristics than those performing standard hours. 2,6,11 Cohort studies utilize a variety of matching methodologies to account for the difference in the characteristics of people practising more intensive dialysis schedules when assessing the impact of these schedules and obtain wide variation in estimates of the survival benefit. 2,6,7,23,24 The present study thus suggests that residual confounding by patient selection in observational studies of extended or more intensive dialysis may be more important that previously acknowledged.…”

“…Observational studies have demonstrated a survival advantage with additional dialysis. 1,2 For instance, the 5-year survival of 70% to 80% seen in cohorts of extended hours haemodialysis (24 h/wk, typically over 3 sessions) 3,4 far exceeds the 50% 5-year survival seen in general haemodialysis cohorts. 5 Yet the quality of the evidence in favour of longer dialysis hours remains low, primarily owing to the dependence on observational data which cannot eliminate residual confounding due to the characteristics of patients or centres choosing to perform intensive haemodialysis.…”

Variability and trends over time and across centres in haemodialysis weekly duration in Australia and New Zealand

“…Longer weekly duration was recorded in HHD than in ICHD, with a wider range of treatment times. A European study assessing treatment duration from the ERA‐EDTA Registry also found that patients on extended‐hours haemodialysis (defined as thrice weekly ≥6 hours sessions) were more often treated at home than patients on conventional haemodialysis (thrice weekly 3.5 to 4‐hours sessions) (6% vs 0%) 12 . In ANZ, no financial incentives or penalties and no official policies or guidelines are in place regarding the required treatment duration.…”

“…In 1981, the National Cooperative Dialysis Study, aiming to develop a definition of adequate long‐term dialysis treatment by evaluating different concentrations of blood urea nitrogen (BUN) and treatment times, found that shorter treatment duration appeared to contribute to morbidity 1 . Since then, many observational studies have associated longer dialysis duration with lower mortality 2‐12 . Among these, a registry analysis from Australia and New Zealand in 2006 concluded that the optimal combination of haemodialysis treatment for better survival appeared to be Kt/V ≥ 1.3 and session length of ≥4.5 hours 6 .…”