Abstract: TH-PO947

Higher Risk of Mortality Among Girls with ESRD Is Mediated by Lower Access to Transplant

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational

Authors

  • Ahearn, Patrick, UCSF, San Francisco, California, United States
  • Johansen, Kirsten L., UCSF, San Francisco, California, United States
  • Grimes, Barbara A., UCSF, San Francisco, California, United States
  • Ku, Elaine, UCSF, San Francisco, California, United States
Background

Although women live longer than men in the general population, survival in the adult ESRD population does not appear to differ by sex. Few studies have focused on differences in survival by sex among children with ESRD.

Methods

Using data from the United States Renal Database Service (USRDS) we performed a retrospective cohort study of children between the ages of 2 and 19 years who required their first RRT between January 1, 1995 and December 31, 2011. We examined the association between sex and mortality using a Cox proportion hazards model adjusted for demographic characteristics, cause of ESRD, socioeconomic status, calendar year of ESRD onset, and BMI.

Results

We included 13,087 children, of whom 1694 died during 7.4 years of mean follow-up. In unadjusted analysis, risk of death was 45% higher for girls than boys (95% CI 1.32-1.60). In fully adjusted analyses, risk of death remained 35% higher for girls (95% CI 1.22-1.48). This higher risk of death was present regardless of initial RRT modality but was more marked in older girls (≥13 years, p<0.05 for interaction). The risk of death for girls was higher both on dialysis and after transplant (p>0.05 for interaction by treatment modality). Girls were also less likely to receive kidney transplant than boys (adjusted HR 0.93 [95% CI 0.90-0.97]). In mediation analysis, when we further adjusted for transplant as a time-dependent covariate in our models for mortality risk, the risk of death in girls was partially attenuated [HR 1.28, Table].

Conclusion

Mortality risk is substantially higher for girls with ESRD than for boys. This risk of death is partially attributable to lower access to transplant among girls. However, even after adjustment for transplant access, risk of death remains higher for girls treated with either dialysis or transplant. Further investigation is needed to determine reasons for these observations.

Risk of death comparing girls versus boys in unadjusted and adjusted analyses.
Overall cohort (N=13,087)Girls
N= 5,951
Hazard ratio
(95% CI)
Boys
N=7,136
Hazard ratio
(95% CI)
Total follow-up time, person-years43,32353,513
Follow-up time attributable to dialysis18,17720,021
Unadjusted model1.45 (1.32-1.60)1.0 (Ref)
Adjusted model1.35 (1.22-1.48)1.0
Adjusted model with transplant as time-dependent covariate1.28 (1.16-1.41)1.0
Risk of death during follow-up time attributed to dialysis1.30 (1.16-1.44)1.0
Risk of death during follow-up time attributed to transplant1.28 (1.03-1.60)1.0

Funding

  • NIDDK Support