Outcomes associated with in-center nocturnal hemodialysis from a large multicenter program

Abstract

Background and objectives: The objective of this study was to evaluate epidemiology and outcomes of a large in-center nocturnal hemodialysis (INHD) program.

Design, setting, participants, & measurements: This case-control study compared patients who were on thrice-weekly INHD from 56 Fresenius Medical Care, North America facilities with conventional hemodialysis patients from 244 facilities within the surrounding geographic area. All INHD cases and conventional hemodialysis control subjects who were active as of January 1, 2007, were followed until December 31, 2007, for evaluation of mortality and hospitalization.

Results: As of January 1, 2007, 655 patients had been on INHD for 51 +/- 73 d. Patients were younger, there were more male and black patients, and vintage was longer, but they had less diabetes compared with 15,334 control subjects. Unadjusted hazard ratio was 0.59 for mortality and 0.76 for hospitalization. After adjustment for case mix and access type, only hospitalization remained significant. Fewer INHD patients were hospitalized (48 versus 59%) with a normalized rate of 9.6 versus 13.5 hospital days per patient-year. INHD patients had greater interdialytic weight gains but lower BP. At baseline, hemoglobin values were similar, whereas albumin and phosphorus values favored INHD. Mean equilibrated Kt/V was higher in INHD patients related to longer treatment time, despite lower blood and dialysate flow rates.

Conclusions: Patients who were on INHD exhibited excellent quality indicators, with better survival and lower hospitalization rates. The relative contributions of patient selection versus effect of therapy on outcomes remain to be elucidated in prospective clinical trials.

Figure 1.

Location of FMCNA facilities that provide INHD as of January 1, 2007, in the United States.

Figure 2.

Kaplan-Meier unadjusted 1-yr survival curves comparing patients on INHD (solid line) with patients on CHD (dotted line) in terms of mortality (A) and hospitalization (B).

Figure 3.

Results from Cox proportional hazard models comparing time to death and time to first hospitalization from patients who were treated by INHD with patients who were on CHD. Case mix–adjusted models included age, gender, race, diabetes, body surface area, and vintage (square root).