Performance Characteristics of Candidate Criteria for Hemodialysis Arteriovenous Fistula Maturation

Abstract

Background: Twenty to 60% of newly created hemodialysis arteriovenous fistulas do not mature adequately for use. One barrier to developing interventions to improve fistula outcomes is a lack of standardized criteria for maturation.

Methods: Using data from the multicenter, prospective Hemodialysis Fistula Maturation (HFM) Study, we determined sensitivities, specificities, and positive and negative predictive values of multiple candidate maturation criteria using the HFM Study maturation criteria as the reference. We also compared, across the maturation criteria, relationships between maturation and fistula survival using Cox proportional hazards models.

Results: We included 535 of the 602 HFM Study participants. The median (interquartile range) age was 57 (47-65) years, 70% were men, and 45% were Black participants. Depending on the criterion and time frame for ascertainment (3, 4, 5, 6, or 9 months), sensitivities ranged from 57% to 100%, specificities ranged from 85% to 100%, positive predictive values ranged from 88% to 100%, and negative predictive values ranged from 65% to 100%. For all criteria, areas under the curve for the 6-month (0.90-0.97 for unassisted maturation and 0.89-0.95 for overall maturation) and 9-month time frames were similar. Attainment of unassisted maturation was associated with lower risks of fistula abandonment, with hazard ratios ranging from 0.10 to 0.40 depending on the criterion and time frame. Eliminating dialysis adequacy indicators, or simplifying the criteria in other ways, had little effect on performance characteristics.

Conclusions: High performance characteristics are maintained with maturation criteria that are simpler and less burdensome to ascertain than the HFM Study outcome measure.

Graphical abstract

Figure 1

Composition of the analytic cohort. HFM, Hemodialysis Fistula Maturation.

Figure 2

Sensitivities and specificities for the candidate maturation criteria for unassisted fistula maturation. The time frames for meeting the maturation criteria are within 3 months (A), within 6 months (B), and within 9 months (C). BPS, blood pump speed; KHI, Kidney Health Initiative; NAVAC, North American Vascular Access Consortium.

Figure 3

AUCs for candidate criteria for unassisted maturation. The time frames for meeting maturation criteria are within 3 months (A), within 6 months (B), and within 9 months (C). AUC, area under the curve; CI, confidence interval. Figure 3 can be viewed in color online at www.cjasn.org.

Figure 4

Hazard ratios for fistula abandonment for fistulas with versus without unassisted maturation on the basis of each maturation criterion applying the 6-month time frame for attaining maturation.