Association of Hemodialysis Treatment Time and Dose With Mortality and the Role of Race and Sex
Received 4 February 2009; accepted 7 August 2009. published online 23 October 2009.
Background
The association of survival with characteristics of thrice-weekly hemodialysis (HD) treatment, including dose or duration of treatment, has not been completely elucidated, especially in different race and sex categories.
Study Design
We examined associations of time-averaged and quarterly varying (time-dependent) delivered HD dose and treatment time and 5-year (July 2001-June 2006) survival.
Setting & Participants
88,153 thrice-weekly–treated HD patients from DaVita dialysis clinics.
Predictors
HD treatment dose (single-pool Kt/V) and treatment time.
Outcomes & Other Measurements
5-Year mortality.
Results
Thrice-weekly treatment time < 3 hours (but ≥ 2.5 hours) per HD session compared with ≥ 3.5 hours (but < 5 hours) was associated with increased death risk independent of Kt/V dose. The greatest survival gain of higher HD dose was associated with a Kt/V approaching the 1.6-1.8 range, beyond which survival gain was minimal, nonexistent, or even tended to reverse in African American men and those with 4-5 hours of HD treatment. In non-Hispanic white women, Kt/V > 1.8 continued to show survival advantage trends, especially in time-dependent models.
Limitations
Our results may incorporate uncontrolled confounding. Achieved Kt/V may have different associations than targeted Kt/V.
Conclusions
HD treatment dose and time appear to have different associations with survival in different sex or race groups. Randomized controlled trials may be warranted to examine these associations across different racial and demographic groups.
1Harold Simmons Center for Chronic Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
2Department of Epidemiology, UCLA School of Public Health, Los Angeles, CA
5David Geffen School of Medicine at UCLA, Los Angeles, CA
6Department of Medicine, Arizona Center on Aging, Arizona Health Sciences Center, Tucson, AZ
7Department of Surgery, Arizona Center on Aging, Arizona Health Sciences Center, Tucson, AZ
8Department of Statistics, UCLA College of Letters and Sciences, Los Angeles, CA
Address correspondence to Kamyar Kalantar-Zadeh, MD, MPH, PhD, Harold Simmons Center for Chronic Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, 1124 West Carson St, C1-Annex, Torrance, CA 90509-2910