ESHOL study reanalysis: All-cause mortality considered by competing risks and time-dependent covariates for renal transplantation.

BACKGROUND: The ESHOL study showed that post-dilution online haemodiafiltration (OL-HDF) reduces all-cause mortality versus haemodialysis. However, during the observation period, 355 patients prematurely completed the study and, according to the study design, these patients were censored at the time of premature termination.

METHODS: The aim of this study was to investigate the outcome of patients who discontinued the study.

RESULTS: During follow-up, 207 patients died while under treatment and 47 patients died after discontinuation of the study. Compared with patients maintained on haemodialysis, those randomised to OL-HDF had lower all-cause mortality (12.4 versus 9.46 per 100 patient-years, hazard ratio and 95%CI: 0.76; [0.59-0.98], P= 0.031). For all-cause mortality by time-dependent covariates and competing risks for transplantation, the time-dependent Cox analysis showed very similar results to the main analysis with a hazard ratio of 0.77 (0.60-0.99, P= 0.043).

CONCLUSION: The results of this analysis of the ESHOL trial confirm that post-dilution OL-HDF reduces all-cause mortality versus haemodialysis in prevalent patients. The original results of the ESHOL study, which censored patients discontinuing the study for any reason, were confirmed in the present ITT population without censures and when all-cause mortality was considered by time-dependent and competing risks for transplantation.