title: Incremental Hemodialysis, Residual Kidney Function, and Mortality Risk in Incident Dialysis Patients: A Cohort Study.
abstract: Maintenance hemodialysis is typically prescribed thrice weekly irrespective of a patient's residual kidney function (RKF). We hypothesized that a less frequent schedule at hemodialysis therapy initiation is associated with greater preservation of RKF without compromising survival among patients with substantial RKF.
  
  
  
  A longitudinal cohort.
  
  
  
  23,645 patients who initiated maintenance hemodialysis therapy in a large dialysis organization in the United States (January 2007 to December 2010), had available RKF data during the first 91 days (or quarter) of dialysis, and survived the first year.
  
  
  
  Incremental (routine twice weekly for >6 continuous weeks during the first 91 days upon transition to dialysis) versus conventional (thrice weekly) hemodialysis regimens during the same time.
  
  
  
  Changes in renal urea clearance and urine volume during 1 year after the first quarter and survival after the first year.
  
  
  
  Among 23,645 included patients, 51% had substantial renal urea clearance (≥3.0mL/min/1.73m(2)) at baseline. Compared with 8,068 patients with conventional hemodialysis regimens matched based on baseline renal urea clearance, urine volume, age, sex, diabetes, and central venous catheter use, 351 patients with incremental regimens exhibited 16% (95% CI, 5%-28%) and 15% (95% CI, 2%-30%) more preserved renal urea clearance and urine volume at the second quarter, respectively, which persisted across the following quarters. Incremental regimens showed higher mortality risk in patients with inadequate baseline renal urea clearance (≤3.0mL/min/1.73m(2); HR, 1.61; 95% CI, 1.07-2.44), but not in those with higher baseline renal urea clearance (HR, 0.99; 95% CI, 0.76-1.28). Results were similar in a subgroup defined by baseline urine volume of 600mL/d.
  
  
  
  Potential selection bias and wide CIs.
  
  
  
  Among incident hemodialysis patients with substantial RKF, incremental hemodialysis may be a safe treatment regimen and is associated with greater preservation of RKF, whereas higher mortality is observed after the first year of dialysis in those with the lowest RKF. Clinical trials are needed to examine the safety and effectiveness of twice-weekly hemodialysis.
authors: Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, CA.
authors: Yoshitsugu
authors: Y
authors: Obi
authors: Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, CA.
authors: Elani
authors: E
authors: Streja
authors: Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, CA.
authors: Connie M
authors: CM
authors: Rhee
authors: Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, CA.
authors: Vanessa
authors: V
authors: Ravel
authors: Department of Medicine, University of California Irvine, Orange, CA.
authors: Alpesh N
authors: AN
authors: Amin
authors: Division of Nephrology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors: Adamasco
authors: A
authors: Cupisti
authors: Division of Nephrology, Huashan Hospital, Fudan University, Yangpu, Shanghai, China.
authors: Jing
authors: J
authors: Chen
authors: Hofstra North Shore-LIJ School of Medicine, Division of Kidney Diseases and Hypertension, North Shore-LIJ Health System, Great Neck, NY.
authors: Anna T
authors: AT
authors: Mathew
authors: Division of Nephrology, University of Tennessee Health Science Center, Memphis, TN; Nephrology Section, Memphis VA Medical Center, Memphis, TN.
authors: Csaba P
authors: CP
authors: Kovesdy
authors: Kidney Research Institute and Harborview Medical Center, Division of Nephrology, University of Washington, Seattle, WA.
authors: Rajnish
authors: R
authors: Mehrotra
authors: Harold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine, Orange, CA; Fielding School of Public Health at UCLA, Los Angeles, CA; Los Angeles Biomedical Research Institute at Harbor-UCLA, Torrance, CA. Electronic address: kkz@uci.edu.
authors: Kamyar
authors: K
authors: Kalantar-Zadeh
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000503:physiopathology* / Q000628:therapy; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000379:methods*; D012306:Risk
keywords: Incremental hemodialysis; dialysis initiation; frequent hemodialysis; interdialytic weight gain; mortality; renal urea clearance; residual kidney function (RKF); standard Kt/V; treatment regimen; twice-weekly hemodialysis