Which targets in clinical practice guidelines are associated with improved survival in a large dialysis organization?

Abstract

Professional organizations have developed practice guidelines in the hope of improving clinical outcomes. The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has set targets for dialysis dosage (single-pool Kt/V), hematocrit, serum albumin, calcium, phosphorus, parathyroid hormone, and BP for hemodialysis (HD) patients. Several guidelines are largely based on results from observational studies. In contrast to other parameters, BP values within the KDOQI guidelines have been associated with increased mortality. Therefore, it was postulated that having multiple parameters that satisfy the current guidelines, except those for BP, is associated with improved survival among HD patients. A retrospective analysis was conducted of incident HD patients who were treated at facilities operated by Dialysis Clinic Inc., a not-for-profit dialysis provider, between January 1, 1998, and December 31, 2004 (n = 13,792). Cox proportional hazards models were used to assess the association between satisfying guidelines and mortality. Values within guidelines for single-pool Kt/V, hematocrit, serum albumin, calcium, phosphorus, and parathyroid hormone were associated with decreased mortality (P < or = 0.0001). The largest survival benefit was found for serum albumin (hazard ratio [HR] 0.27; 95% confidence interval [CI] 0.24 to 0.31). Satisfying these six guidelines simultaneously was associated with an 89% reduction in mortality (HR 0.11; 95% CI 0.06 to 0.19]). Conversely, BP values satisfying the guideline were associated with increased mortality (HR 1.90; 95% CI 1.73 to 2.10). Because this target was largely extrapolated from the general population, a randomized, controlled trial is needed to identify the optimal BP for HD patients.