Racial/Ethnic Disparities in Anemia Complications in Patients with ESRD

In 2016, more than half a million people in the United States were affected by end-stage renal disease (ESRD). ESRD represents a significant economic burden on the healthcare system. Anemia is a common modifiable complication of chronic kidney disease (CKD) and is more pronounced in later CKD stages. Patients with anemia are at increased risk for left ventricular hypertrophy, heart failure, cognitive impairment, and poorer quality of life; anemia is also a key predictor of mortality.

Erythropoiesis-stimulating agents (ESAs) are first-line treatments for anemia; however, use of those agents is associated with safety concerns. In 2011, a series of policy changes adopted in the United States combined to change incentives around the use of ESAs. The Centers for Medicare & Medicaid Services implemented the Medicare ESRD prospective payment system (PPS) that altered financial incentives by allowing providers to retain payments above Medicare’s reimbursement level while providing dialysis services. The system reduced the incentive to provide treatments that had been reimbursed on a fee-for-service basis, including injectable medications such as ESAs.

Also in 2011, the US FDA revised the prescribing advice for ESAs with guidance on a more conservative use of the agents for renal anemia. That same year, the ESRD Quality Incentive Payment was implemented to improve quality of care by applying a penalty for poor management of dialysis patients, including the overuse of ESAs. The three policy changes resulted in a shift in transfusions from an outpatient to an inpatient setting. However, there are few data available on the effect of the changes on care and outcomes in an inpatient setting.

According to Nga TQ Nguyen and colleagues at the Centre for Public Health School of Medicine, Dentistry, and biomedical Sciences, Queens University Belfast, Belfast, UK, race/ethnicity adds a layer of complexity to the potential impact of the policy changes. The researchers conducted a study aimed at examining the impact of PPS on the likelihood of an inpatient episode for ESRD being recorded with anemia following the adoption of PPS as well as its effect on hospital costs, inpatient mortality, and discharge destination. The second outcome of interest was the impact of PPS on ethnic disparities with a particular focus on the experience of Native Americans. Results of the study were reported online in BMC Nephrology [doi.org/10.1186/s12882-020-02081-4].

The researchers utilized data from the National Inpatient Sample–Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. All admissions with a primary diagnosis of ESRD and a procedure/diagnosis code referring to any type of renal replacement therapy were identified using International Classification of Diseases (ICD) Ninth and Tenth Revisions codes. Episodes with a code indicating acute kidney injury were excluded. From the resulting cohort, episodes that involved anemia due to CKD were identified using ICD codes.

Over a 9-year period (2008-2016), there were 591,683 admissions with ESRD. Of those, the proportions of episodes of care related to White, Native, Black, Asian, and Hispanic Americans were 39.8%, 0.95%, 36.6%, 3.4%, and 16.4%, respectively. In 2008, the percentage of inpatient episodes with recorded anemia arising from CKD was 26.2%; in 2016, the percentage was 50.0%.

At admission, mean age ranged from 57.0 years among Black Americans to 64.8 years among Asian Americans. The predominant insurance was Medicare; only a small percentage in each racial group had private insurance (the smallest percentage was among Native Americans, 7.1%).

Black Americans had the highest percentage of patients receiving hemodialysis as RRT modality (92.8%), followed by Native Americans (92.5%). Diabetes was most prevalent in admissions who were Native American; 42.7% had diabetes with complications and 29.2% had diabetes without complications. Approximately 42.3% of episodes among Native Americans with ESRD and 37.8% of those among White Americans with ESRD had anemia recorded as a diagnosis.

In the fully adjusted model, compared with White Americans, the odds of anemia were highest for Native Americans (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.15-1.25) and Asian Americans (OR, 1.20; 95% CI, 1.17-1.22), followed by Hispanic Americans (OR, 1.12; 95% CI, 1.10-1.13) and Black Americans (OR, 1.04; 95% CI, 1.03-1.05). The risk of anemia was higher in patients with iron deficiency, diabetes with complications, lower age-adjusted Charlson comorbidity index score, age ≤50 years or ≥80 years compared with other groups.

Over the 9-year study period, all ethnicities have a higher likelihood of a diagnosis of anemia compared with White American admissions. In 2011, there was a sharp increase in the likelihood of anemia for all ethnicities, followed by a steady increment in subsequent years.

Results from the fully adjusted regression model of the impact of PPS on recorded anemia found that the odds ratio of recorded anemia after PPS was 1.42 (95% CI, 1.40-1.44) compared with the preceding period. Following PPS, the odds of inpatient mortality for admissions with anemia compared to admissions without anemia increased; the odds ratio for admissions with anemia dying in the hospital rose from 0.61 (95% CI, 0.56-0.67) to 0.72 (95% CI, 0.68-0.76) between 2008 and 2010 and 2011-2016. The likelihood of discharge to another healthcare facility increased, and costs per inpatient episode fell during the same periods. Minorities, including Native American admissions, were less likely to die in the hospital, less likely to be discharged to another healthcare facility, and, with the exception of Black American admissions, were more expensive to treat.

The researchers cited some limitations to the study findings, including the significant increase in the number of individuals in the United States identified as mixed race, the use of ICD codes to identify health status, outpatient data not collected on the same annual basis as inpatient data, and the cross-sectional nature of the data based on each single hospitalization limiting the ability to examine patterns related to factors such as readmissions.

In conclusion, the researchers said, “We found a significant increase in anemia recorded as a complication among ESRD hospitalizations in the US following the adoption of PPS. We found ethnic disparities in the recorded anemia as a complication among ESRD admissions, a gap that was most evident among Native American admissions and that widened for all racial/ethnic groups following the introduction of the PPS. The study demonstrated the potential unintended consequence of measures targeting behavior in one part of the healthcare system to have a material impact on other parts in terms of both equity and efficiency.”

Takeaway Points

  1. A series of policy changes in 2011 changed reimbursement arrangements and guidance on the use of erythropoiesis-stimulating agents for the treatment of patients with end-stage renal disease with anemia.
  2. Researchers conducted a study to examine trends in anemia in ESRD hospitalization and to analyze disparities in inpatient outcomes among ethnic groups following the changes.
  3. Following the changes, there was an increase in anemia recorded as a complication among ESRD admissions. The study also demonstrated the existence of ethnic disparities that widened following the policy changes.