Action Points

DALLAS -- The rates of death and of hospitalizations for patients on dialysis hit a peak about a decade ago before entering a steady fall, two analyses found.

Unadjusted mortality rates for patients followed up to 1 year fell for both new and continuing dialysis patients from 2003 to 2011, said researchers at a poster session here at the National Kidney Foundation's spring clinical meeting.

For incident patients, mortality rates increased by more than 10% from 1996 to 2003, from 27.8 to 30.6 deaths per 100 patient years. But that trend reversed in the following years until 2011 -- rates decreased by more than 15%, from 30.6 to 26.0.

For prevalent patients, mortality rates didn't change from 1996 to 2003, but dropped from 22.5 in 2003 to 18.3 in 2011.

"Declining mortality rates are the clearest evidence of improving outcomes in dialysis patients," said lead author Eric Weinhandl, MS, a PhD candidate at the University of Minnesota, in Minneapolis. "The transition to dialysis is difficult, both physically and psychologically," he added.

Data were taken from the Centers for Medicare and Medicaid Services End Stage Renal Disease database. Cohorts were followed until recovery of renal function, kidney transplant, interruption of outpatient dialysis for more than 3 months, or death. The maximum follow-up duration was 1 year.

The team was interested in whether the trend was across all groups or concentrated among certain groups, and found that "it's a pretty consistent trend across all groups," Weinhandl said. Those ages 18 to 44 saw the biggest decrease (-4.2% per year), along with white Hispanics (-3.9%), African Americans (-3.6%) and peritoneal dialysis patients (-3.9%).

The change in 2003 was likely multifactorial, Weinhandl said in an interview with MedPage Today. "It may very well be that there's just a confluence of events that happened, and they all gathered enough critical mass that things began to change," he said.

Generic cardiovascular medication in 2002 allowed for better management of cardiovascular diseases, there were increased rates of vaccination against influenza, and there was a decreased reliance on catheters, which can cause infections. Additionally, changes in anemia treatment around 2005 could have contributed to some of the later decline, said Weinhandl.

But for the first-year incident patients, the rate remains high, the researchers noted. "There's a lot of work to be done for that first year," said Weinhandl. "The number is still much higher than in the prevalent population, and there's still a lot of room for improving outcomes in that first-year population."

In a separate study using the same database, the researchers found that hospitalization rates among dialysis patients have also been falling, but they peaked a couple of years later, around 2005. Rates for incident patients increased from 1997 to 2005 from 2.54 to 2.57 admissions per patient-year. But rates fell by 8.2% from 2005 to 2011, from 2.57 to 2.36.

For prevalent patients, the rate was unchanged until 2005, then fell 8.4% from 2005 to 2011, from 2.02 to 1.85 admissions per patient year. Cardiovascular disease rates also fell for prevalent dialysis patients from 2005 to 2011. The steepest decrease for both dialysis groups occurred from 2008 to 2011.

The researchers also found that infection rates in the hospital have largely stayed the same from 2005 to 2011. This could contribute to the higher risk of mortality among incident patients demonstrated in the other study, said Weinhandl. "There's probably a relationship between the infection rate not changing very much, and the fact that the incident population has been difficult to move, because there is where you've got catheters, and you've got a high risk of infection that can lead to death," he said.

The highest risk for incident patients is concentrated in the first few years, said Weinhandl. "The vast majority of new patients start with a catheter -- nearly 80%," he said. "It's not easy to solve, but there's still a lot of opportunity to improve things for the first few years."

More research needs to be done surrounding the declining hospitalization rates, according to the investigators. "Premature discharge from the hospital may place dialysis patients at increased risk of rehospitalization," they said. "The relatively rapid decline in hospitalized days in recent years merits further attention."

Researchers disclosed no relevant relationships with industry.

• Reviewed by F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine

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