SAT-024 EFFECT OF HAEMODIALYSIS SESSION FREQUENCY AND DURATION ON SURVIVAL IN AUSTRALIAN END-STAGE KIDNEY DISEASE PATIENTS: A COHORT STUDY

Abstract

End-stage kidney disease (ESKD) patients have substantially increased mortality compared to the general population. Intensive haemodialysis (HD) of more frequent and or longer duration treatment has been proposed to improve survival in this population. However, it is not clear whether the improved survival observed in studies is attributed to increased frequency, increased duration, or both. We aimed to examine the independent effects of session frequency and session duration on mortality in incident ESKD patients initiating HD. A retrospective cohort study of HD patients was performed using data from Australian and New Zealand Dialysis and Transplant Registry (ANZDATA). The cohort included all patients aged ≥18 years who initiated HD of ≥3 sessions/week in Australia from 2001 to 2015. Indigenous patients and patient who received <90 days of HD were excluded. Initial dialysis prescription was categorised as 3 sessions/week compared to >3 sessions/week, and session durations ≤5 hours/session compared to >5 hours/session. The outcome of interest was patient mortality. Survival analysis was performed using Cox regression analysis, with multivariable analysis controlling for available covariates. In total, 16,944 patients were included in survival analyses with a combined follow up time of 54478.2 person-years. Both frequent and extended duration HD was associated with improved survival in univariate analysis with >3 sessions having a 44% reduced risk of mortality (HR = 0.56; 95% CI 0.48-0.64) and >5 hours session duration having a 68% reduced mortality risk (HR = 0.32; 95% CI 0.26-0.39). After controlling for frequency and other covariates, patients initiated on HD sessions >5 hours had a significantly reduced risk of mortality compared with patients with HD session ≤5 hours (adjusted HR = 0.57; 95% CI 0.44-0.74). In contrast, patients initiated on >3 sessions of HD per week had a similar risk of death when compared with patients on 3 sessions of HD per week (adjusted HR = 0.97; 95% CI 0.84-1.13), independent of session duration. Longer duration HD rather than increased frequency of treatment appears to reduce mortality in HD patients receiving at least 3 sessions per week. This has significant potential implications for management and requires further study.