Racial/Ethnicity Differences in Initial Hemodialyis Access

Compared with white patients, black patients and Hispanic patients tend to initiate hemodialysis with an arteriovenous fistula (AVF) less frequently. That was among the findings of a retrospective analysis conducted recently by Devin S. Zarkowsky, MD, and colleagues. Analysis results were reported online in JAMA Surgery [doi:10.1000/jamasurg.2015.0287].

Use of AVF at first hemodialysis has been shown to be associated with superior outcomes compared with intravascular hemodialysis catheters (IHCs). In 2010, 593,086 individuals in the United States had end-stage renal disease (ESRD); of those, 383,992 were treated with hemodialysis.

Previous studies stratified by race/ethnicity have suggested that minority patients tend to receive inferior incident hemodialysis access, either with arteriovenous grafts or IHCs. Minority patients often have higher comorbidity and/or socioeconomic challenges limiting their access to the healthcare system. Concern about increased surgical risk leads to increased use of IHCs, and lack of medical insurance coverage can delay placement of permanent hemodialysis access, resulting in not enough time to mature a fistula before starting hemodialysis.

According to the researchers, actual differences in demographics between white versus black versus Hispanic ESRD populations and the effect of these differences on incident hemodialysis access are not known. Utilizing the US Renal Data System (USRDS) database, this analysis assessed national trends in incident hemodialysis access with respect to race/ethnicity (both overall and stratified by comorbid disease), receipt of nephrology care, and medical insurance status.

The analysis included all ESRD patients in the USRDS who initiated hemodialysis between January 1, 2006, and December 31, 2010. Univariable statistics and logistic regression were used to compare race/ethnic groups (white vs black vs Hispanic) and multivariable logistic regression and propensity score-matching techniques evaluated hemodialysis access rates between patients of different races/ethnicities with comparable characteristics. The main outcomes and measures were utilization rates of AVF, arteriovenous graft, and IHC.

The study cohort included 396,075 patients. Most (55.4%) were white, 30.3% were black, and 14.3% were Hispanic. More white patients initiated hemodialysis with an AVF compared with black or Hispanic patients (18.3% vs 15.5% and 14.6%, respectively; P<.001). The dominant access mode was an IHC, used in 312,351 patients (78.9%) among the cohort. The most common causes of ESRD were diabetic nephropathy (43.2%) and hypertension (29.4%).

Overall, black and Hispanic patients were younger than white patients (mean age, 58.8 years vs 59,8 years vs 67.0 years, respectively; P<.001), and more likely to be female (48.1% vs 43.3% and 41.4%, respectively; P<.001). In addition, white patients had more comorbidities, including congestive heart failure, coronary artery disease, peripheral arterial disease, chronic obstructive pulmonary disease, and cancer (P<.001 for all).

Black and Hispanic patients had less frequent nephrology care compared with white patients (57.9% vs 54.0% vs 63.2%, respectively; P<.001) and were uninsured more often compared with white patients (11.7% vs 14.1% vs 4.4%, respectively; P<.001).

Categorized by type of incident hemodialysis access, white patients had a 22% greater chance of initiating hemodialysis with an AVF, compared with black patients (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.20-1.24) and a 32% greater chance of initiating hemodialysis with an AVF than Hispanic patients (OR, 1.32; 95% CI, 1.28-1.35).

Black patients had 80% greater odds of having a functional AVG at initial hemodialysis compared with white patients (OR, 1.80; 95% CI, 1.74-1.86) and 97% higher odds than Hispanic patients (OR, 1.97; 95% CI, 1.87-2.08). Initiation of hemodialysis with an IHC was highest among Hispanic patients, compared with white patients (OR, 1.29; 95% CI, 1.26-1.33).

Across all hemodialysis access groups, Medicare was the most common medical insurance regardless of race/ethnicity. Black patients and Hispanic patients initiating hemodialysis with any access modality were significantly more likely to have no medical insurance or Medicaid compared with white patients (P<.002).

Comparison of similar groups was done by stratifying the racial/ethnic groups by medical insurance status (no insurance vs Medicaid vs Medicare vs private insurance). Regardless of medical insurance status, black patients and Hispanic patients initiated hemodialysis with an AVF less frequently than white patients.

Following stratification by medical insurance states, black patients (ORs, 0.90; 95% CI, 0.82-0.98 for uninsured and 0.85; 95% CI, 0.84-0.87 for insured) and Hispanic patients (ORs, 0.72; 95% CI, 0.65-0.81 for uninsured and 0.81; 95% CI, 0.79-0.84 for insured) persistently initiated hemodialysis with an AVF less frequently than white patients (P<.05 for all).

Among patients in the uninsured population, Hispanic patients initiated hemodialysis with an AVF less frequently than black patients (P<.001). Among those with Medicare, incident AVF use was similar between black and Hispanic patients. Regardless of medical insurance status, black patients initiated hemodialysis with an AVG more often than white patients or Hispanic patients.

Of patients who had no nephrology care, AVF use was higher among black patients (OR, 1.29; 95% CI, 1.18-1.40; P<.001) and Hispanic patients (OR, 1.13; 95% CI, 1.02-1.26; P=.02) compared with white patients. AVF use was similar among patients who had nephrology care for <6 months. Among those who had nephrology care for >1 year, AVF utilization at initial hemodialysis was lower among black patients (OR, 0.81; 95% CI, 0.78-0.84) and Hispanic patients (OR, 0.86; 95% CI, 0.82-0.90) compared with white patients (P<.001 for both comparisons).

“Black patients and Hispanic patients initiate dialysis using AVFs significantly less frequently than white patients despite their being younger and having fewer comorbidities. These disparities persisted independent of factors that drive health access for fistula placement, such as medical insurance statues and nephrology care. The sociocultural underpinnings of these disparities deserve investigation and redress to maximize the benefits of initiating hemodialysis via fistula in patients with ERDS irrespective of race/ethnicity,” the researchers said.

Takeaway Points

  1. Use of an arteriovenous fistula (AVF) at initiation of hemodialysis has been shown to be associated with improved outcomes, but the influence of race/ethnicity on patterns of AVF utilization are unknown.
  2. In this study, more white patients initiated hemodialysis with an AVF than black patients or Hispanic patients, even when stratified by medical insurance status.
  3. Among patients with nephrology care >1 year, AVF use at hemodialysis initiation was also lower among black patients and Hispanic patients