Provider visit frequency and vascular access interventions in hemodialysis

Abstract

Background and objectives: Medicare reimbursement policy encourages frequent provider visits to patients with ESRD undergoing hemodialysis. This study sought to determine whether more frequent face-to-face provider (physician and advanced practitioner) visits lead to more procedures and therapeutic interventions aimed at preserving arteriovenous fistulas and grafts, improved vascular access outcomes, and fewer related hospitalizations.

Design, setting, participants, & measurements: Multivariable regression was used to evaluate the association between provider (physician and advanced practitioner) visit frequency and interventions aimed at preserving vascular access, vascular access survival, hospitalization for vascular access infection, and outpatient antibiotic use in a cohort of 63,488 Medicare beneficiaries receiving hemodialysis in the United States. Medicare claims were used to identify the type of vascular access used, access-related events, and vascular access failure.

Results: One additional provider (physician and advanced practitioner) visit per month was associated with a 13% higher odds of receiving an intervention to preserve vascular access (95% confidence interval [95% CI], 12% to 14%) but was not associated with vascular access survival (hazard ratio, 1.01; 95% CI, 0.99 to 1.03). One additional provider visit was associated with a 9% (95% CI, 5% to 14%) lower odds of hospitalization for vascular access infection and a corresponding 9% (95% CI, 5% to 14%) higher odds of outpatient intravenous antibiotic administration. However, the associated changes in absolute probabilities of hospitalization and antibiotic administration were small.

Conclusions: More frequent face-to-face provider (physician and advanced practitioner) visits were associated with more procedures and therapeutic interventions aimed at preserving vascular accesses, but not with prolonged vascular access survival and only a small decrease in hospitalization for vascular access.

Keywords: and outcomes; arteriovenous fistula; arteriovenous graft; chronic hemodialysis; economic analysis; epidemiology.

Figure 1.

Study population selected from incident patients with ESRD. Of 666,718 patients who developed ESRD between January 1, 2004, and December 31, 2009, we selected 63,488 for this analysis.

Figure 2.

Vascular access survival difference by visit frequency is small: above- and below-median visit frequency. (A) Arteriovenous (AV) fistula graft survival. (B) AV graft survival. Visits were divided into upper and lower halves of mean visits. “Fewer” visits refer to patients with ≤3.6 visits per month, while “more” visits refer to patients with >3.6 visits per month. P values for log-rank test of equivalence of survival distributions were 0.02 for grafts and 0.001 for fistulas.

Figure 3.

Predicted probability of vascular access repair increases with more frequent visits, while probabilities of vascular access failure, access preserving interventions, and hospitalization for vascular access infections are largely unchanged. Probabilities were obtained by averaging predicted probabilities across the entire study population. From logistic regression results, monthly probabilities were converted to annual probabilities multiplicatively, while accounting for differences in time since vascular access placement over the course of a year. To estimate annual probabilities of vascular access survival, we used a parametric survival model assuming an exponential survival distribution. (See Supplemental Appendix, “Methods for Creating Figure 3,” as well as Supplemental Tables 11 and 12).