Extended-hours hemodialysis offers substantially longer treatment time compared to conventional hemodialysis schedules and is associated with improved fluid and electrolyte control and favorable cardiac remodeling. However, whether extended-hours hemodialysis improves survival remains unclear. Therefore, we determined the association between extended-hours compared to conventional hemodialysis and the risk of all-cause mortality in a nationally representative cohort of patients initiating maintenance dialysis in the United States from 2007 to 2011. Survival analyses using causal inference modeling with marginal structural models were performed to compare mortality risk among 1206 individuals undergoing thrice weekly extended-hours hemodialysis or 111,707 patients receiving conventional hemodialysis treatments. The average treatment time per session for extended-hours hemodialysis was 399 minutes compared to 211 minutes for conventional therapy. The crude mortality rate with extended-hours hemodialysis was 6.4 deaths per 100 patient-years compared with 14.7 deaths per 100 patient-years for conventional hemodialysis. In the primary analysis, patients treated with extended-hours hemodialysis had a 33% lower adjusted risk of death compared to those who were treated with a conventional regimen (95% confidence interval: 7% to 51%). Additional analyses accounting for analytical assumptions regarding exposure and outcome, facility-level confounders, and prior modality history were similar. Thus, in this large nationally representative cohort, treatment with extended-hours hemodialysis was associated with a lower risk for mortality compared to treatment with conventional in-center therapy. Adequately powered randomized clinical trials comparing extended-hours to conventional hemodialysis are required to confirm these findings.
Kidney international. 2016 Aug 20 [Epub ahead of print]
Matthew B Rivara, Scott V Adams, Sooraj Kuttykrishnan, Kamyar Kalantar-Zadeh, Onyebuchi A Arah, Alfred K Cheung, Ronit Katz, Miklos Z Molnar, Vanessa Ravel, Melissa Soohoo, Elani Streja, Jonathan Himmelfarb, Rajnish Mehrotra
Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington, USA. Electronic address: ., Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington, USA; Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA., Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, Washington, USA., Harold Simmons Center for Kidney Disease Research & Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Irvine, California, USA., Department of Epidemiology, UCLA Fielding School of Public Health, Los Angeles, California, USA; UCLA Center for Health Policy Research, Los Angeles, California, USA., Division of Nephrology & Hypertension, Department of Internal Medicine, University of Utah, and Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah, USA., Division of Nephrology, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA.