Comparison of Nocturnal Hemodialysis (NHD) and Short Daily Hemodialysis (DHD) With the NxStage® System One™

End Stage Renal Disease (ESRD) continues to be a devastating clinical condition. The number
of patients in 2004 affected by ESRD in the United States rose to 472,000. More than 104,000
new patients began therapy for ESRD in 2004 (1.5% greater than in 2003), while the prevalent
dialysis population reached nearly 336,000 (3.4% higher). Total Medicare costs for ESRD in
2004 rose to $20.1 billion while non-Medicare costs rose to $12.4 Billion(1).

Treatment options for ESRD patients are currently limited to either transplantation or
dialysis. As daily hemodialysis (DHD) continues to gain widespread acceptance in the
dialysis community, there is also renewed interest in nocturnal hemodialysis (NHD) therapy.

NHD has the potential to provide certain advantages over both DHD and conventional
thrice-weekly in-center HD. NHD typically consists of 6 - 10 hour treatments while the
patient sleeps, providing more gentle fluid removal, more time for equilibration, improved
hemodynamic stability and superior clearance of larger solutes(2).

The proposed study plans to explore whether or not NHD is equivalent to DHD on a per
treatment basis, using the NxStage System One in the home setting.

1. USRDS 2006 Annual Data Report: Atlas of End-Stage Renal Disease in the United States,
NIH, NIDDK, Bethesda, MD, 2006

2. Lacson E, Diaz-Buxo J: Daily and Nocturnal Hemodialysis: How do they stack up? American
Journal Kidney Disease, Vol 38(2) Aug 2001: 225-239.

Inclusion Criteria:

- Patients must have a stable prescription in the short daily home environment using
the NxStage System One prior to enrollment.

Exclusion Criteria:

- Patients are not eligible if:

- they are currently enrolled in another drug or device study which could impact
the successful completion of this study

- they are currently on NHD, or less than 3 months since discontinuing NHD

- if they were previously enrolled in this study.