Reliable access to the bloodstream is essential to successful treatment of end-stage renal disease (ESRD) with maintenance hemodialysis. Patients typically receive hemodialysis three times a week; the vascular access is the patient’s lifeline.
There are three types of hemodialysis vascular access: (1) arteriovenous fistula (AVF); (2) arteriovenous graft (AVG); and (3) central venous catheter (CVC). Numerous studies have found reduced morbidity and mortality in patients dialyzing with an AVF. Compared with patients with an AVF, in those with a CVC rates of cardiovascular events and all-cause and infection-related mortality are higher.
To achieve twin goals of improving health outcomes and lowering costs, the Centers for Medicare & Medicaid Services (CMS) promote the use of AVFs. In 2002, CMS created the Fistula First Initiative, with an initial goal of AVF use in 40% of prevalent hemodialysis patients; the goal was subsequently increased to 66%. Currently, the CMS Quality Incentive Program provides a financial incentive for providers to increase CVF use by imposing reimbursement penalties on dialysis units based in part on prevalence of AVFs.
The earlier studies have not included evaluation of the costs related to AVF management in a representative hemodialysis population in the United States. Mae Thamer, PhD, and colleagues recently conducted a retrospective observational study utilizing national claims data to examine the costs to Medicare of vascular access creation, maintenance, and associated complications. Results of the study were reported in the American Journal of Kidney Diseases [2018;72(1):10-18].
Patients were stratified into cohorts based on timing of AVF creation relative to initiation of hemodialysis therapy. Costs were evaluated over 2.5 years of follow-up based on clinical outcomes. Study participants were elderly US Medicare beneficiaries who initiated hemodialysis therapy from 2010 to 2011. The study predictor was AVF primary and secondary patency and nonuse during the first year after AVF creation. The outcome of interest was annualized vascular access costs per patient per year.
The three study cohorts were (1) cohort 1 initiated hemodialysis therapy with a mature AVF (n=2704); (2) cohort 2 initiated hemodialysis therapy with a CVC and a maturing AVF (n=3530); and (3) cohort 3 initiated hemodialysis therapy with a CVC only and an AVF was created within 9 months of initiation of hemodialysis therapy (n=3901).
The AVF was placed approximately 5 months (median, 144 days) prior to dialysis therapy initiation in patients in cohort 1, who were less likely to be institutionalized, more likely to ambulate, had less cardiac and pulmonary disease, and had higher concentrations of albumin compared with the other two cohorts (P<.001 for all comparisons). There were also more women and a higher proportion of patients with ESRD in cohort 1 compared with cohorts 2 and 3 (P<.001). Compared with cohorts 1 and 2, those in cohort 3 were more likely to live in areas with the lowest median household income and were significantly less likely to have nephrology care prior to initiation of dialysis therapy (49% vs 8.0% for cohort 1 and 26.3% for cohort 2).
Of the patients in cohorts 2 and 3 who initiated hemodialysis therapy using a CVC with or without a maturing AVF, 46% of AVFs were not used for hemodialysis. Of AVFs that were used for hemodialysis, 40% to 63% required ≥1 interventional or surgical procedure before the first AVF use, and 70% to 80% required ≥1 interventional or surgical procedure within 1 year of creation. Patients in cohort 1 were more likely to maintain AVF patency in the first year (P<.001 for all comparisons). If the AVF was successfully used, subsequent abandonment of the AVF in the first year (secondary patency loss) was similar between groups (9.5% to 10.6%; pairwise comparisons P<.04).
In the first year after AVF creation, total mean annualized per patient per year vascular access costs were lowest for patients whose AVF maintained patency in year 1 compared with patients whose AVF experienced primary or secondary patency loss in year 1 (eg, $8576 vs $16,428 and $18,989, respectively, in cohort 3; P<.001). The highest costs were accrued in patients whose AVFs were not used for hemodialysis (eg, $32,405 in cohort 3; P<.001 for all comparison). These relationships were seen across all three cohorts.
In the second year after AVF creation, total per person per year access costs were lower than in the first year; the trends seen in the first year continued in the second year. Vascular access costs were again lower in patients whose AVFs maintained primary patency in year 2 than in patients whose AVFs experienced primary or secondary patency loss in year 1 or in patients who experienced AVF nonuse. Costs for patients with secondary patency loss or AVF nonuse were three to four times higher than for patients who maintained primary patency in year 1 (eg, $5479 vs $17,350 and $17,000, respectively, in cohort 3; P<.001 for both comparisons).
In the 2.5 years after AVF creation, mean vascular access costs per patient per year were $7871 for AVFs that maintained primary patency in year 1, $13,282 for AVFs that experienced primary patency loss in year 1, $17,808 for AVFs that experienced secondary patency loss in year 1, and $31,630 for AVFs that were not used. Patterns were similar across all three cohorts.
In 2013, fee-for-service Medicare paid approximately $2.8 billion for services related to dialysis vascular access, accounting for approximately 12% of all payments related to ESRD. Of that amount, 50.1% was for inpatient care related to vascular access procedures or complications, 39.6% for invasive imaging and endovascular procedures, 8.6% for open surgical procedures performed on outpatients, 1.1% for anesthesia used in vascular access procedures, and 0.6% for noninvasive diagnostic imaging procedures.
Limitations cited by the authors included the inability to calculate vascular access costs for predialysis procedures and costs, lack of data on why such a large percentage of fistulas (nearly half) were never used, the lack of data for Medicare health maintenance organization patients or those with non-Medicare claims, lack of a comparison of costs between AVFs and AVGs, and only capturing costs from the perspective of the third-party payer.
In summary, the researchers said, “This study suggests that AVFs that experience dysfunction in the first year after creation, especially those that are never used for hemodialysis, result in substantially higher long-term costs. There remains an unmet clinical need for improving outcomes and reducing avoidable costs after AVF surgical creation.”
- Researchers conducted a retrospective observational study to examine costs and resources associated with creating and maintaining arteriovenous fistula (AVF) vascular access for patients on maintenance hemodialysis.
- AVF failure in the first year after creation is common; costs were substantially higher for those with AVF failure in the first year.
- In 2013, fee-for-service Medicare paid $2.8 billion for services related to dialysis vascular access, approximately 12% of all payments for end-stage renal disease.