The 2021 USRDS Annual Data Report (ADR) is a massive undertaking and a wealth of information pertaining to patients with kidney disease. In this interview, AJKD Interview Editor Timothy Yau @Maximal_Change talks to Kirsten Johansen @kljohansenmd, Director of the United States Renal Data System (USRDS) database, to get some insights into the annual report, how it is compiled, and how to best use it.
AJKDBlog: Please give our readers a little background on the USRDS database. Can you tell us how the information is collected, and how it has evolved over the years?
The USRDS is more of a hodge-podge of data than a single database. It started as an ESRD registry mandated by congress in the Omnibus Budget Reconciliation Act of 1986. The first report (covering only ESRD) was produced in 1989 (as a book that was mailed to stakeholders!). Since the beginning, data on the ESRD population has been derived primarily from Medicare (originally through the Health Care Financing Administration, now through the Centers for Medicare & Medicaid Services (CMS).
In June 2012, the workflow was converted from a paper-based system to CROWNWeb (Consolidated Renal Operations in a Web-enabled Network) to allow certified dialysis facilities to transmit patient data to CMS electronically. This system has just been replaced by the End Stage Renal Disease Quality Reporting System (EQRS). Data on kidney transplant recipients comes from EQRS and from the United Network for Organ Sharing (UNOS). We build the ESRD database each year using data from EQRS (previously CROWNWeb) and UNOS merged with the CMS Enrollment Database to allow us to link with claims data for Medicare beneficiaries.
The USRDS was expanded to include patients with non-dialysis dependent chronic kidney disease (CKD) in 2006. This population cannot be comprehensively catalogued in the United States. Instead, we rely on different data sources including Medicare claims data and private insurance databases to examine outcomes in these patients. Because there is no source of data that identifies all patients with CKD in the United States, we use data from the National Health and Nutrition Examination Survey (NHANES) to estimate the prevalence of CKD in the US population.
AJKDBlog: I can’t imagine the amount of work involved in collecting and organizing this kind of data. No wonder there are literally hundreds of pages and figures to go through in the annual report. I appreciate the way it is presented, and the new format that began two years ago makes it easy to navigate to the various sections. What happened behind the scenes to make the change to the new platform rather than the traditional PDF document?
A lot! Our vision was to create an interactive format that would allow readers to navigate through the ADR more easily without having to download entire chapters as PDFs. We wanted readers to be able to retrieve information of interest by key subgroups more readily than had been possible before. We also wanted options to customize figures for presentations to visually represent the data of greatest interest. Although we had a clear vision, we needed help with the web design and were fortunate to find a great group to work with us. There was a learning curve to figuring all this out, and we improved the process the second time through by allowing our team to make corrections and edits directly. I hope next year will be even better.
AJKDBlog: The annual report shows that about 14% of the population has CKD, a number that has been relatively stable over many years. However, the distribution of CKD stage has shifted slightly, with more patients having CKD 1-2 with albuminuria and stable GFR. What does this change suggest in your opinion?
It looks like a good news/bad news situation. The prevalence of CKD declined within key risk groups, including those with diabetes and cardiovascular disease, suggesting that medical management of these conditions may have improved over the interval. However, the prevalence of obesity, diabetes, and hypertension increased over the same period. So, it looks like increasing rates of obesity, hypertension, and diabetes offset progress achieved through lower rates of CKD within these groups, highlighting the importance of addressing these major risk factors in efforts to reduce the overall burden of CKD.
These factors may also drive some of the disparities observed in CKD and ESRD. Although rates of CKD are higher among Black and Hispanic than among white individuals, the degree of disparity increases substantially over the course of kidney disease. Black patients are still three times more likely to reach ESRD as their white counterparts. Some of this disparity appears to be driven by earlier onset and higher rates of diabetes and hypertension and faster progression of CKD. We explore these disparities and the contributions of access to care and social determinants of health in greater detail in the 2021 ADR in a new supplemental chapter on racial and ethnic disparities.
AJKDBlog: There was a 2.7% increase in patients with ESKD in 2019, with 85% of those patients initiating in-center hemodialysis. With the new Kidney Health Initiative pushing for more preemptive transplants and home dialysis, what are the trends we are seeing, and how can we increase uptake for these options?
The percentage of patients initiating home dialysis has been increasing over the last decade from a nadir of about 6% in 2008 to about 12% in 2019. That rise has accelerated in the last few years, perhaps because of incentives prior to the Executive Order in 2019 (and the resolution of peritoneal dialysis [PD] supply shortages that slowed growth a few years back). So, we’re going in the right direction already, and we are poised to observe the effects of a new set of incentives.
To answer the second part of your question, I think it comes down to education. We need to figure out how to incorporate high quality education about dialysis modalities into nephrology practice and make it available to all patients with advanced kidney disease. We should also educate new in-center hemodialysis patients, particularly those who may have “crashed” into dialysis and not received modality education beforehand. The second thing is support and infrastructure. If we are to sustain a large increase in home dialysis, we will need more PD nurses, and we will need to be able to perform PD in hospitals and nursing homes when patients are admitted. We should also consider in-home support for PD if we really want to increase the eligible population.
AJKDBlog: The 2021 annual report also includes a COVID-19 supplement which is a wealth of information. We covered some of this in NephMadness 2021, but based on this data, can you discuss how the pandemic uniquely affect patients with kidney disease?
COVID-19 has had a huge impact on the ESRD and CKD populations. Although rates of COVID-19 diagnosis and hospitalization among patients on dialysis were highly correlated with rates in the general population in 2020, they were much higher. For example, by the end of 2020, almost 16% of all Medicare beneficiaries who had been receiving dialysis at the beginning of the year had been diagnosed with COVID-19! Hospitalization rates were extremely high as well; about 40 times higher for dialysis patients in the first half of the year than for the general population. Considering Medicare beneficiaries, dialysis patients were initially hospitalized at more than 10 times the rate of those without CKD. Rates were about 5 times higher for transplant recipients and around three times higher for those with CKD.
Sadly, those infections and hospitalizations translated into deaths. Overall mortality increased by 18% among patients receiving dialysis in 2020 and by 19% among transplant recipients over rates in 2019. This excess mortality, combined with a decrease in kidney transplantation and dialysis initiation in the first wave of the pandemic, led to the first ever decrease in the prevalent ESRD population. ProPublica published a story about this in which they characterized dialysis populations as “the pandemic’s perfect victims.”
AJKDBlog: Absolutely. Whenever someone minimizes the effects of COVID-19 (“it’s just the flu”, “no one gets really sick from it”, etc), it’s important to remember these numbers for patients on dialysis. I know there’s so much to go over, but in your opinion, what are some of the biggest takeaways from 2021 that sets this annual report apart from years past?
In terms of the report itself, I think the COVID-19 information sets it apart. It included more recent data highlighting the immense impact on our patients in hopes of providing a rationale for our patients to have access to and priority for vaccinations (and now to treatments for COVID-19). In addition, there are two new chapters never before included in the ADR. First, a chapter on home dialysis provides more detail and will help us track outcomes as new payment models are rolled out. Second, a chapter on racial and ethnic disparities in CKD and ESRD explores the contributions of access to care and neighborhood-level socioeconomic factors and social determinants of health.
As far as takeaways from the results in the 2021 ADR, it occurred to us that 2019 (the latest period of data for most parts of the ADR) will serve as a reference point for a lot of changes coming in 2020 and beyond. Next year’s ADR will include 2020 and the effects of COVID-19 on all aspects of care for patients with CKD and ESRD. Shortly thereafter, we will begin to see effects of new payment models. Looking back at some highlights over the last decade, I think the big trends include the following: