Mortality rates among dialysis patients dropped significantly from 2007 to 2012, with corresponding drops in hospital admission rates, according to analyses presented at the American Society of Nephrology’s Kidney Week.

Among outpatient dialysis providers, mortality slowed from 22.5 per 100 patient years to 17.1 per 100 patient years, a drop of 24% among prevalent patients in outpatient centers, according to Allan Collins, MD, president of the PEER Kidney Care Initiative. PEER is funded by a consortium of 14 dialysis providers and the Chronic Disease Research Group at the University of Minnesota.

According to the Medicare data, mortality was as high as 23% in 1999, then saw a gradual decline. Preliminary review of 2013 Medicare patient data shows the mortality rate going down even further, Collins told NN&I.

Data presented by the U.S. Renal Data System during Kidney Week from recently released 2015 Annual Data Report shows similar results among all dialysis patients, with a 28.2% decline in the death rate for prevalent patients from 1999-2013. The largest drop came from 1999-2006.

Other data from the 2015 ADR includes:

  • Mortality rates for kidney transplant patients have fallen by 40% since 1996.
  • Adjusted mortality rates in 2013 per 1,000 patient-years were 172 for hemodialysis patients and 152 for peritoneal dialysis patients.
  • Patterns of mortality during the first year of dialysis differ substantially by modality. For hemodialysis patients, reported mortality is very high in the second month, but declines thereafter. In contrast, mortality rises slightly over the course of the year for peritoneal dialysis patients, USRDS researchers wrote.
  • The relationship between race and mortality differs considerably by age among dialysis patients. Among dialysis patients younger than 45 years old, Whites have mortality rates comparable to Blacks; however, in older age groups, Whites have higher mortality rates than their Black counterparts.

 

Incident rates and early deaths among dialysis patients

Dialysis patients continue to have substantially higher mortality, and fewer expected remaining life years, compared to the general population and Medicare populations with cancer, diabetes, or cardiovascular disease, the USRDS noted.

Adjusted survival for hemodialysis patients who were incident in 2008 is only 55% at three years after ESRD onset. For peritoneal dialysis patients, adjusted survival is 66% at three years. Still, survival has improved. Between the 2000 and 2008 incident ESRD cohorts for all modalities, five-year survival rose from 35% to 40% among hemodialysis patients, from 37% to 50% among peritoneal dialysis patients, from 66% to 75% among deceased donor transplant patients, and from 75% to 87% among living donor transplant patients. Within this cohort, adjusted survival was consistently higher among younger patients, among Asians and blacks compared to other races, and patients among with primary cause of ESRD designated as glomerulonephritis compared to patients with diabetes or hypertension.

“The decline in mortality shown in this chapter has important implications for both patients and resource allocation, as increasing ESRD patient lifespan is likely contributing to the ongoing increase in the size of the prevalent ESRD population,” the USRDS said in its report.

Why are mortality rates down among dialysis patients?

Collins presented PEER’s review of Medicare data pointing to possible explanations for the reduction in mortality.

More fistulas, fewer catheters. The mission of the Fistula First Breakthrough Initiative, approved by the Centers for Medicare & Medicaid Services in November 2005 to encourage more fistula placement, may be bearing fruit. Collins says fistula placement rates among dialysis patietns more than doubled from 1999 to 2012, stabilized and declined with an estimated fistula count of 62% in prevalent patients, and 17% of patients with catheters. The decline suggests that more fistulas are maturing and continue to work effectively. “The decline in mortality rates is coincident with a fall in catheter placement rates and rise in fistula placements as well as other changes in practice,” Collins noted during his ASN presentation.

Likewise, the decline in death rates may be linked with an overall decline in hospital admission rates among incident dialysis patients since 2007. Mid-Atlantic and East North Central regions of the country have seen the largest drop in patients going to the hospital, Collins reported, with a sharp drop in admission rates from 2011-2012.

Specifically during that two–year period:

  • Hospitalizations for congestive heart failure fell significantly
  • Infectious hospitalizations decreased, including vascular access infection hospitalizations, without an increase in bacteremia/sepsis admissions

He speculated during his talk that the ESRD payment bundle, introduced in 2011, may have had an influence to the dramatic drop, as well as changes to black box warnings for erythropoiesis stimulating agents (ESAs) that called for reducing dosages. Increasing fistulas and more intensive nutritional support for patients may also be a factor, he said.