USRDS data show declining incidence rate, but more patients with transplants, on home dialysis
This year’s Annual Data Report from the United States Renal Data System is an atypically brief one. In the second section of the Annual Data Report, which is dedicated to end-stage kidney disease, there are both exciting hints of progress and signs of continued lack of progress.1
This article will review the highlights in both categories.
Perhaps the most significant news is a 2.7% decrease in the standardized incidence rate of ESKD between 2016 and 2017. This represents the second largest year-over-year decrease in the rate since 1980. In real terms, the number of patients who either initiated dialysis or received a preemptive kidney transplant fell from 125,408 in 2016 to 124,500 in 2017. This is promising evidence that the epidemic of ESKD in the United States has slowed.
Nevertheless, there is room for skepticism. In 2017, Medicare began to cover dialytic treatment of AKI in outpatient dialysis facilities. This change in coverage may have subtly altered the epidemiology of ESKD incidence. In past years, a small proportion of patients with newly diagnosed ESKD initiated dialysis and then recovered kidney function. Among patients who initiated hemodialysis in 2008 and 2009, almost 6% experienced sustained recovery of kidney function; in the subset of patients whose primary cause of ESKD was acute interstitial nephritis (AIN) or acute tubular necrosis (ATN), approximately 40% experienced sustained recovery of kidney function.2 In 2017, patients with AKI due to AIN or ATN could have initiated outpatient dialysis and then recovered kidney function or died, but without diagnosis of ESKD.
We will need time to understand the effect of outpatient dialysis for AKI on the apparent incidence of ESKD.
Gains seen in home dialysis
Modality mix in both the incident and prevalent dialysis patient populations continues to rotate toward home dialysis. In the incident patient population, the percentage of patients on home hemodialysis (HHD) increased from 0.3% in 2016 to 0.4% in 2017— a large relative increase — while the percentage of patients on peritoneal dialysis (PD) increased from 10% in 2016 to 10.4% in 2017. Total utilization of either HHD or PD among incident dialysis patients reached its highest level since 1997. In the prevalent patient population, total utilization of either HHD or PD was 11.9% in 2017, also its highest level since 1997. By the end of 2017, there were more than 62,000 patients dialyzing at home in the United States.
From the perspective of numbers alone, now is the time for CMS to become more serious about evaluating the quality of dialysis in the home setting; numerous quality measures in the CMS Quality Incentive Program continue to exclude patients on HHD and/or PD.
In contrast to modality mix, the mix of vascular accesses in use exhibits little change. Among incident patients undergoing hemodialysis, the percentage of patients using a catheter resides stubbornly at approximately 80%, although one in five of these patients have a maturing fistula or graft. For reasons including lack of health care insurance, inadequate monitoring of the progression of chronic kidney disease and even a patient’s denial of the future need for dialysis, the United States has simply been unable to reduce catheter dependence at dialysis initiation.
Among prevalent patients undergoing hemodialysis, the percentage of patients using a fistula or graft also resides at 80%. Whether this share can or should increase further is admittedly unclear. Per the Dialysis Outcomes Practice Patterns Practice Monitor, catheter utilization is nearly 50% in Canada.3 However, 5-year survival there is roughly equal to 5-year survival in the United States.4
Rise and fall of mortality
The death rate among dialysis patients appears to have stagnated, as a preliminary report on the USRDS data suggested.5 Since 2014, the adjusted death rate in all dialysis patients has varied between 163 and 166 deaths per 1,000 patient-years; in concrete terms, a rate of 165 deaths per 1,000 patient-years indicates that for every 100 patients alive on Jan. 1, approximately 85 patients will be alive on Dec. 31. In both the hemodialysis and peritoneal dialysis subsets, static death rates are also evident.
This story stands in stark contrast to the trend that characterized the first decade of this century, during which the adjusted death rate in all patients on dialysis fell by almost 23%. Why the trajectory has changed is unclear. It is tempting to hypothesize that dialytic factors alone are primarily responsible.
Several key performance indicators, including vascular access mix and hemodialysis session duration, have been very stable in recent years. However, lurking outside the dialysis patient population is an unprecedented uptick in the age-adjusted death rate in the general population, largely due to an increase in cardiovascular death.6 From that perspective, even a static death rate among patients on dialysis outpaces the death rate in the broader environment. This raises an interesting question, vis-à-vis the survival of patients on dialysis: Have the rules of engagement shifted, such that the nature of dialysis itself will have less influence than external pressures on patient health?
The domain of kidney transplantation continues to evolve. The percentage of patients on dialysis who were waitlisted for a transplant declined again between 2016 and 2017, to a new low of less than 14%. Changes in December 2014 to the Kidney Allocation System are probably responsible for this downturn, as the incentive for early listing was eliminated. Nevertheless, the question remains whether only one in seven patients on dialysis are good candidates for a kidney transplant. Against this backdrop, data from the USRDS show that kidney transplantation itself has continued to increase. There were approximately 15,000 deceased donor transplants in 2017, a new high in this century. The number of living donor transplants remained slightly below 6,000.
As a new decade begins, the picture of ESKD in the United States is a mix of progress, stagnation and evolution. The days of compounding growth in the incidence of ESKD appear to be far behind us. This is a welcome development. Kidney transplantation has made noticeable strides during the past 5 years, thus relieving some pressure on the dialysis delivery system. This is also a welcome development. However, in the gap between ESKD incidence and kidney transplantation is a large population of patients on dialysis with an array of intermediate and clinical outcomes that seem to be unyielding.
Thus, the question before all of us is this: What can be done to move this population once again?
In the short run, the COVID-19 pandemic has rearranged priorities. However, there are clues about how to move forward. Infection control is a major focus today, but it should also be a focus in the future, with initiatives aimed at vascular access infection and seasonal influenza. Home dialysis can permit patients to shelter in place today, but in the future, home dialysis offers opportunities for prescription customizability and self-care.
Ultimately, ESKD is a chronic disease with a well-known identity. The core challenges that characterized it in 2019 are probably the same in 2021. Considering concurrent changes in the mortality of the general and dialysis patient populations, one could argue that those challenges are improving cardiovascular health and confronting all the exogenous social factors that place pressure not only on patients on dialysis, but also on U.S. citizens with functioning kidneys. From this point of view, dialysis is not a niche state of chronic disease, but instead a sentinel state. What we – physicians, nurses, government officials, researchers and allied advocates – can accomplish to improve the health and quality of life of patients on dialysis may foreshadow the course of chronic disease management in the United States during the next decade, especially among Medicare members with multimorbidity. Nephrology can lead the way.
- US Renal Data System 2019 Annual Data Report: Epidemiology of Kidney Disease in the United States. Am J Kidney Dis. 2019.
- Mohan S, et al. PLoS One. 2013;doi:10.1371/journal.pone.0083447.
- Arbor Research Collaborative for Health. DOPPS Practice Monitor: Canada; 2018.
- Canadian Institute for Health Information. Annual Statistics on Organ Replacement in Canada: Dialysis, Transplantation and Donation, 2009 to 2018.
- Weinhandl E, et al. Am J Nephrol. 2019;doi:10.1159/000500943.
- Kochanek KD, et al. Deaths: Final data for 2017. National Vital Statistics Reports. Vol 68.
- For more information:
- Eric D. Weinhandl, PhD, MS, is with the Chronic Disease Research Group, Hennepin Healthcare Research Institute, Minneapolis. He is also with the department of pharmaceutical care and health systems at the University of Minnesota. He can be reached at email@example.com.