The recently released US Renal Data System (USRDS) 2021 Annual Data Report provides a detailed look at the epidemiology of COVID-19 in the kidney disease population during 2020, the first year of the pandemic.
Following the emergence of the pandemic in 2020, approximately 1 in 13 (7.7%) Medicare beneficiaries with CKD, 1 in 10 (9.4%) Medicare kidney transplant recipients, and 1 in 6 (15.8%) Medicare beneficiaries receiving maintenance dialysis had been diagnosed with COVID-19.
In addition, during the first wave of the pandemic, the weekly number of patients initiating dialysis declined sharply. In week 15 (April 5-April 11), 2030 patients initiated dialysis, which was about 30% below historical norms, according to the report. The report’s authors stated, “The apparent deficit of patients initiating dialysis gradually closed during the second quarter of 2020, with weekly numbers of incident [end-stage kidney disease (ESKD)] patients in line with historical norms during the second half of 2020 and the first quarter of 2021. This pattern was evident for members of all subgroups defined by age, sex, and race/ethnicity.”
“Indeed, the weekly rate of new dialysis starts at the beginning of the second quarter of 2020 fell to a level not seen in about a decade,” James B. Wetmore, MD, MS, Deputy Director of the USRDS and medical director for nephrology research for the Chronic Disease Research Group, told Renal & Urology News. Much of the slowdown could be related to patients deferring dialysis until a later time, he said. Another possibility is that patients who were approaching ESKD and would have transitioned to dialysis or kidney transplantation prior to the pandemic died before they could make the transition, he said.
During the spring 2020 wave of the pandemic, the percentage of deaths among patients receiving maintenance dialysis due primarily to COVID-19 peaked at 11.8% in week 18 (April 26- May 2), according to the report.
The percentage peaked at 10.0% in week 31 of the summer wave (July 26-August 2) and, during the winter wave, the percentage peaked at 19.9% in week 1 of 2021 (January 3-9). Thus, during this week, about 1 in 5 deaths that occurred among patients receiving maintenance dialysis were attributed to COVID-19. The percentage of deaths due primarily to COVID-19 then declined steadily during the first half of 2021.
With regard to all-cause mortality among dialysis patients, the cumulative number of deaths was 82,561 during 2018 and 83,797 during 2019. “During the early part of 2020, the cumulative number of deaths tracked prior years, aside from growth due to the steadily increasing size of the dialysis patient population,” the report stated. “However, beginning in March, the cumulative number of deaths deviated from historical trends.”
By the end of 2020, there were 98,897 deaths, an increase of 18% from 2019. “The cumulative number of deaths during the first half of 2021 followed the track of deaths in 2020,” suggesting ongoing effects of the pandemic into 2021.
CKD Prevalence Declines
The report also provided data on other kidney disease trends. It noted that the prevalence of CKD among adults decreased among some key risk groups, including older individuals and those with diabetes and cardiovascular disease. The prevalence of these risk factors, however, increased over the same period.
“Thus, some success in prevention of CKD among high-risk individuals was offset by an increase in the number of individuals with these underlying high-risk conditions,” the report reads.
The report includes data from adults surveyed in 2015-2018 as part of the National Health and Nutrition Examination Survey (NHANES). The data showed that, overall, 14.4% of the US adult population — about 1 in 7 individuals — had CKD based on a low estimated glomerular filtration (eGFR) or albuminuria (on a single examination).
The prevalence of CKD, defined as an eGFR less than 60 mL/min/1.73 m2 or albumin-creatinine ratio of 30 mg/g or higher, among individuals aged 65 years or older decreased from 43.2% in 2003-2006 to 36.8% in 2015-2018. Between those periods, the prevalence of CKD decreased from 41.5% to 36.3% among adults with diabetes and from 47.1% to 38.3% among those with cardiovascular disease.
Diabetes prevalence increased from 2003-2006 to 2015-2018 among individuals with and without CKD, reaching 9.7% among those without CKD and 32.8% of those with CKD.
Individuals with CKD had a higher proportion of sedentary patients than those without CKD (26.1% vs 21.6% in 2015-2018).
“Increasing rates of obesity, hypertension, and diabetes offset all 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,” the reported stated. “The need for prevention of risk factors for CKD can be appreciated by considering lifestyle factors. There has been some reduction in sedentary behavior over time, but more than one quarter of those with CKD remained sedentary in 2015-2018.”
ESKD Incidence Rises
In 2019, 130,400 individuals were newly diagnosed with end-stage kidney disease (ESKD), a 2.5% increase from the previous year and 15.1% increase from a decade ago, according to the report. The adjusted incidence (which takes into account changes in the structure of the population, such as differences in the age distribution and the racial/ethnic composition of the U.S. that evolve over time), however, actually decreased from a peak of 418 per million population (pmp) in 2006 to 373 pmp in 2019, an 11% decrease from 2006.
From 2009 to 2019, the adjusted ESKD incidence decreased by 17.5% among Black patients, 14.1% among Native American patients, 12.1% among Hispanic patients, 5.2% among Asian patients, and 2.4% among White patients.
In 2019, 85% of patients with incident ESKD started in-center hemodialysis.
In 2019, the prevalence of ESKD reached 782,818 individuals in 2019, an increase of 40.4% from 2009. The adjusted ESKD prevalence increased to an all-time high of 2252 cases pmp in 2019, according to the report.
One particularly notable trend was the increase in the use of home dialysis. From 2009 to 2019, the proportion of incident dialysis patients performing home dialysis rose from 6.8% to 12.6% and the proportion of patients performing home dialysis at 1 year after dialysis initiation increased from 10.5% to 18.2%, according to the report. Most of this was due to an increase in the use of peritoneal dialysis. The proportion of patients initiating kidney replacement therapy with peritoneal dialysis climbed from 6% to 11% over this period. One trend that may prove worrisome to the nephrology community is the lack of increase in the use of preemptive kidney transplantation, which remained unchanged at only 3% of incident patients over the decade.
US Renal Data System. 2021 Annual Report. Published online December 14, 2021.