Temporal risk profile for infectious and noninfectious complications of hemodialysis access

Abstract

Vascular access complications are a major cause of morbidity in patients undergoing hemodialysis, and determining how the risks of different complications vary over the life of an access may benefit the design of prevention strategies. We used data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) to assess the temporal profiles of risks for infectious and noninfectious complications of fistulas, grafts, and tunneled catheters in incident hemodialysis patients. We used longitudinal data to model time from access placement or successful treatment of a previous complication to subsequent complication and considered multiple accesses per patient and repeated access complications using baseline and time-varying covariates to obtain adjusted estimates. Of the 7769 incident patients identified, 7140 received at least one permanent access. During a median follow-up of 14 months (interquartile range, 7-22 months), 10,452 noninfectious and 1131 infectious events (including 551 hospitalizations for sepsis) occurred in 112,085 patient-months. The hazards for both complication types declined over time in all access types: They were 5-10 times greater in the first 3-6 months than in later periods after access placement or a remedial access-related procedure. The hazards declined more quickly with fistulas than with grafts and catheters (P<0.001; Weibull regression). These data indicate that risks for noninfectious and infectious complications of the hemodialysis access decline over time with all access types and suggest that prevention strategies should target the first 6 months after access placement or a remedial access-related procedure.

Figure 1.

Derivation of the incident and prevalent cohorts, and distribution of the noninfectious and infectious events.

Figure 2.

Crude rates and modeled hazards for noninfectious (left) and infectious events (right) in fistulas (diamond), grafts (circles), and catheters (squares). Dots with 95% confidence interval whiskers represent crude rates of complications per access-month plotted at the mid-point of the time interval. Dashed lines represent the hazard estimates from the Weibull models (models 1; Table 3). There were 1401 incident patients at risk at 24 months, 695 at 30 months, and 332 at 36 months.