Characteristics and survival of patients with end stage renal disease and spina bifida in the United States renal data system

Abstract

Purpose: We describe the characteristics, treatments and survival of patients with spina bifida in whom end stage renal disease developed from 2004 through 2008 in the United States Renal Data System.

Materials and methods: We used ICD-9-CM code 741.* to identify individuals with spina bifida using hospital inpatient data from 1977 to 2010, and physician and facility claims from 2004 to 2008. We constructed a 5:1 comparison group of patients with end stage renal disease without spina bifida matched by age at first end stage renal disease service, gender and race/ethnicity. We assessed the risk of mortality and of renal transplantation while on dialysis using multivariate cause specific proportional hazards survival analysis. We also compared survival after the first renal transplant from the first end stage renal disease service to August 2011.

Results: We identified 439 patients with end stage renal disease and spina bifida in whom end stage renal disease developed at an average younger age than in patients without spina bifida (41 vs 62 years, p <0.001) and in whom urological issues were the most common primary cause of end stage renal disease. Compared to patients with end stage renal disease without spina bifida those who had spina bifida showed a similar mortality hazard on dialysis and after transplantation. However, patients with end stage renal disease without spina bifida were more likely to undergo renal transplantation than patients with spina bifida (HR 1.51, 95% CI 1.13-2.03). Hospitalizations related to urinary tract infections were positively associated with the risk of death on dialysis in patients with end stage renal disease and spina bifida (HR 1.42, 95% CI 1.33-1.53).

Conclusions: Spina bifida was not associated with increased mortality in patients with end stage renal disease on dialysis or after renal transplantation. Proper urological and bladder management is imperative in patients with spina bifida, particularly in adults.

Keywords: chronic; dialysis; kidney failure; spinal dysraphism; transplantation; urinary tract infections.

Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Cumulative incidence of transplantation and death in patients with ESRD and SB, and in matched cohort without SB in 2011 USRDS. Probability of transplantation by 6, 36 and 60 months after starting dialysis was 0.035, 0.14 and 0.18, significantly less than 0.055, 0.24 and 0.29, respectively, in matched nonSB cohort.

Figure 2

Cause specific HRs of average yearly UTI hospitalizations by death on dialysis in multivariate Cox models adjusted for age, race/ethnicity, gender, ESRD primary cause and comorbid conditions in patients with SB only and stratified by age in 2011 USRDS. In patients with ESRD and SB hazard of death on dialysis increased by 42% for each additional annual UTI hospitalization.

Figure 3

Kaplan-Meier survival curves of transplanted patients with ESRD and SB, and matched comparison group without SB. There was no statistical difference in patient survival after first renal transplantation (p = 0.18). Values in parentheses indicate transplantation events.