Background: Little is known about how urea reduction ratio (URR) and hemoglobin (Hb) level relate as clinical performance measures (CPMs) in dialysis facilities. This study examined the relationship between these CPMs as a reflection of underlying processes.
Study design: Cross-sectional observational.
Setting & participants: 47,465 records from 18,003 patients dialyzed in 270 End-Stage Renal Disease Network 5 facilities during the final quarter of 2004.
Predictor & outcome: Facility aggregate Hb level and URR, respectively; both expressed as (1) continuous variables and (2) dichotomous indicators based on established quality thresholds.
Measurements: Weighted regression analyses were used to determine the: (1) association between CPMs and (2) likelihood of missing the performance threshold for one if also missing the other benchmark.
Results: The association between facility URR and Hb level was minimal, with an adjusted mean increase (beta) in URR of 0.91% +/- 0.38% for each 1-g/dL increment in Hb level (P < 0.0001) and R(2) of 0.02. The adjusted odds ratio of a facility failing to meet the URR quality threshold if missing the Hb level benchmark was 2.08 (P < 0.0001). The C statistic for the associated receiver operator characteristic curve was 0.64, with insignificant change when including Hb performance as a predictor of URR performance.
Limitations: Inability to incorporate historic performance or ascertain facility process traits that influence CPMs.
Conclusions: There was minimal association between facility URR and Hb level. The limited concordance in facility performance for these CPMs points to distinct processes that determine quality for each.