Hemodialysis Vascular Access: Practitioner Level Long-term Catheter Rate

Measure Specification

Several observational studies have demonstrated an association between type of vascular access used for hemodialysis and patient mortality1-4. Long term catheter use is associated with the highest mortality risk while arteriovenous fistula use has the lowest mortality risk. Arteriovenous grafts (AVG) have been found to have a risk of death that is higher than AVF but lower than catheters.

The measure focus is the process of assessing long term catheter use at chronic dialysis facilities. This process leads to improvement in mortality as follows: Measure long term catheter rate → Assess value → Identify patients who do not have an AV Fistula or AV graft → Evaluation for an AV fistula or graft by a qualified dialysis vascular access provider → Increase Fistula/Graft Rate → Lower catheter rate → Lower patient mortality.

When this measure was originally developed and specified, the evidence to support the measure was based largely on the National Kidney Foundation (NKF) KDOQI Clinical Practice Guideline for Vascular Access published in 2006. The NKF recently made substantial revisions to these guidelines that were released on 3/12/20. Please see: Lok CE, Huber TS, Lee T, et al; KDOQI Vascular Access Guideline Work Group.

KDOQI clinical practice guideline for vascular access: 2019 update. Am J Kidney Dis. 2020;75(4)(suppl 2):S1-S164. https://www.ajkd.org/article/S0272-6386(19)31137-0/fulltext. The revised guidelines emphasize a patient-focused approach that recommends the development of an End Stage Kidney Disease (ESKD) Life-Plan, and urges providers to not only consider the current vascular access, but subsequent access needs as well in the context of a comprehensive evaluation of the patient’s lifetime with ESKD.

In general, the evidence for the above guidelines has been rated as either low or moderate, with many of the guidelines relying on expert opinion. The evidence review team focused on 16 studies and noted that bloodstream infections were significantly lower among patients who started HD with an AV fistula or AV graft versus a catheter. While three studies from 2015-2016 consistently demonstrated lower mortality with AV fistula or an AV graft compared to a catheter, the studies were considered to be of low quality with moderate risk of bias.

Thus, the workgroup refrained from recommending AV fistula on the basis of lower mortality compared to catheter use, instead relying on the evidence indicating lower blood stream infections. The new guidelines point out the potential for bias in prior studies comparing vascular access types, vascular access complications, and patient outcomes. Specifically, the workgroup notes that the differences in AV fistula and AV graft patency are uncertain, and that AV fistula complication rates in the literature may not be generalizable to all AV fistula.

Of the studies that the evidence review team for the guidelines considered when evaluating outcomes such as patient survival and access patency, only five were from 2015 or later. These are all observational studies, although some are from national registries such as USRDS or ANZDATA that accurately represent the population considered for the measure.

These studies are consistent with prior work that indicates that AV fistula are associated with better patient survival when compared with dialysis catheters5-6, 8-9, and that this is true even in older patients9. However, AV fistula are more likely to require additional surgeries to achieve a functional access5 when compared to AV grafts. This is offset by AV grafts requiring more procedures to maintain patency during the first year after creation7.

This measure contains one strata defined by a single submission criteria. This measure produces a single performance rate. For the purposes of MIPS implementation, this patient-periodic measure is submitted a minimum of once per patient per timeframe specified by the measure for the performance period. The most advantageous quality data code (QDC) will be used if the measure is submitted more than once for the specified timeframe.

If more than one QDC is submitted during the episode time period, performance rates shall be calculated by using the most advantageous QDC. This is an inverse measure which means a lower calculated performance rate for this measure indicates better clinical care or control. The “Performance Not Met” numerator option for this measure is the representation of the better clinical quality or control.

Submitting that numerator option will produce a performance rate that trends closer to 0%, as quality increases. For inverse measures, a rate of 100% means all of the denominator eligible patients did not receive the appropriate care or were not in proper control.