Improvements in dialysis patient mortality are associated with improvements in urea reduction ratio and hematocrit, 1999 to 2002

Background: Benefits in terms of reductions in mortality corresponding to improvements in Kidney Disease Outcomes Quality Initiative (K/DOQI) compliance for adequacy of dialysis dose and anemia control have not been documented in the literature. We studied changes in achieving K/DOQI guidelines at the facility level to determine whether those changes are associated with corresponding changes in mortality. Methods: Adjusted mortality and fractions of patients achieving K/DOQI guidelines for urea reduction ratios (URRs; ≥65%) and hematocrit levels (≥33%) were computed for 2,858 dialysis facilities from 1999 to 2002 using national data for patients with end-stage renal disease. Linear and Poisson regression were used to study the relationship between K/DOQI compliance and mortality and between changes in compliance and changes in mortality. Results: In 2002, facilities in the lowest quintile of K/DOQI compliance for URR and hematocrit guidelines had 22% and 14% greater mortality rates (P < 0.0001) than facilities in the highest quintile, respectively. A 10-percentage point increase in fraction of patients with a URR of 65% or greater was associated with a 2.2% decrease in mortality (P = 0.0006), and a 10-percentage point increase in percentage of patients with a hematocrit of 33% or greater was associated with a 1.5% decrease in mortality (P = 0.003). Facilities in the highest tertiles of improvement for URR and hematocrit had a change in mortality rates that was 15% better than those observed for facilities in the lowest tertiles (P < 0.0001). Conclusion: Both current practice and changes in practices with regard to achieving anemia and dialysis-dose guidelines are associated significantly with mortality outcomes at the dialysis-facility level.

Index words:  End-stage renal disease (ESRD) , quality improvement , dose of dialysis , anemia management , standardized mortality ratio (SMR) , hemodialysis (HD) survival