Abstract: FR-PO870

Understanding Early Mortality after Dialysis Initiation: The Role of Severity of Illness, AKI, and ESRD Certification

Session Information

Category: Dialysis

  • 607 Dialysis: Epidemiology, Outcomes, Clinical Trials - Non-Cardiovascular

Authors

  • Steffick, Diane, University of Michigan, Ann Arbor, Michigan, United States
  • He, Kevin, Kidney Epidemiology and Cost Center, University of Michgian, Ann Arbor, Michigan, United States
  • Yin, Maggie, University of Michigan, Ann Arbor, Michigan, United States
  • Bragg-Gresham, Jennifer L., University of Michigan, Ann Arbor, Michigan, United States
  • Shahinian, Vahakn B., University of Michigan, Ann Arbor, Michigan, United States
  • Heung, Michael, University of Michigan, Ann Arbor, Michigan, United States
  • Saran, Rajiv, University of Michigan, Ann Arbor, Michigan, United States
Background

Analysis of CMS-certified ESRD patient mortality has consistently shown an increase in the first weeks after dialysis initiation, peaking at 6-8 weeks and then declining. The factors underlying this mortality pattern are unclear. To explore this, we examined mortality rates from the first dialysis session, which often occurs prior to ESRD certification for many patients, for those patients on Medicare prior to ESRD.

Methods

This retrospective cohort study used the Medicare 5% sample of patients with a dialysis claim, merged with the USRDS ESRD database. Patients had no dialysis in 2005 and their first claim in 2006-2014 was selected. Patients with an ESRD first service date before the first dialysis claim were excluded. Poisson regression was used to calculate weekly mortality rates, standardized to the sample mean age, sex and race.

Results

N=55,478 patients had a first dialysis claim. 69% began as inpatients (39% ICU), 72% had a diagnosis of AKI, and 41% were eventually certified as ESRD. Most AKI patients who were never certified as ESRD started as inpatients (88%, 60% ICU) with high week 1 mortality that increased further in week 2 and then declined. ESRD-certified patients without AKI at first dialysis showed more gradual increase in mortality rates, peaking around week 11 and again at week 24. Only 29% started as inpatients (6% ICU). Non-AKI patients never certified as ESRD were more likely to start as inpatients (48%, 14% ICU) than the ESRD-certified. 69% of AKI patients that were ESRD certified started as inpatients, with 34% in the ICU [Figure].

Conclusion

Severity of illness at the time of dialysis initiation (with or without AKI) seems to drive the high early mortality seen following dialysis initiation. Low mortality rates at the time of ESRD certification are likely an artifact of clinical decision making that channels early survivors into the ESRD program.

Funding

  • NIDDK Support