Women Less Likely to Have AVFs at Dialysis Initiation

Studies have shown gender disparities in care for many chronic diseases, and ESRD is no exception.

Studies from the early 2000s suggested that women had lower rates of hemodialysis initiation using an arteriovenous fistula (AVF), the preferred hemodialysis vascular access. A recent study in Hemodialysis International analyzed gender-related differences in AVF use at dialysis initiation, including variations between ESRD regional networks.

Mariana Markell, MD, and colleagues of SUNY Downstate School of Medicine, Brooklyn, analyzed US Renal Data System data on 202,999 patients initiating hemodialysis between 2006 and 2009. The analysis was limited to 187,577 patients who received predialysis nephrology care. The study examined gender disparities in AVF use at hemodialysis initiation, with adjustment for a wide range of potential confounders.

The results showed a persistent gender gap during the study period: 18.2% of women had an AVF at dialysis initiation, compared to 25.8% of men. On adjusted analysis, the rate of AVF use at dialysis initiation was 30% lower in women compared to men: odds ratio (OR) 0.69.

A wide range of other factors were also associated with a lower likelihood of AVF at initiation. These included lower body mass index; presence of diabetes, peripheral arterial disease, congestive heart failure, or chronic obstructive pulmonary disease; history of alcohol abuse; inability to ambulate; and being uninsured. The strongest factor was inability to ambulate: odds ratio 0.49. An AVF was more likely to be present in patients who had more than 12 months of predialysis nephrology care: OR 1.89, compared to those with less than 6 months of nephrology care.

The data also showed significant variations in AVF gender disparity between ESRD regions. Region 2 (New York) and region 12 (Midwest) had the largest disparities: OR 0.58 and 0.54, respectively. The disparity was smallest in region 16 (Alaska and Pacific Northwest) and region 18 (California): OR 0.80 and 0.79, respectively. Only region 16 had no statistically significant difference by gender.

The gender disparity was larger for black women compared to non-black women: OR 0.66 versus 0.70. Differences in gender disparity in AVF use were more pronounced in the youngest (19 to 45) and oldest (76 and older) age groups.

The findings add to previous reports of gender disparities in AVF use at dialysis initiation. These differences are present in all age groups and across races, and after controlling for other important patient and clinical characteristics.

The study also shows variations in AVF gender disparities across ESRD networks. Absolute rates of AVF use at dialysis initiation range as low as 15%—far below the 50% rate targeted by the “Fistula First” initiative.

While many factors could contribute to these differences, the findings suggest that practice-based factors may play an important role, Markell said.

“Further studies investigating physician or patient bias, geographic referral patterns, maturation failure and other reasons for access choice should be performed with gender as a focus, in order that all patients may have appropriate access to ‘Fistula First,’ regardless of gender or geographic location,” he said.

Markell M, et al. Gender disparity in fistula use at initiation of hemodialysis varies markedly across ESRD networks—Analysis of USRDS data. Hemodial Int 2017 Jun 29. doi: 10.1111/hdi.12579

March 2018 (Vol. 10, Number 3)