The association of eGFR reporting with the timing of dialysis initiation

Abstract

Automated reporting of eGFR by laboratories has been widely implemented during the last decade. Over this same period, a steady increase in eGFR at dialysis initiation has been reported. This study examined trends in eGFR at dialysis initiation over time among incident dialysis patient populations before and after eGFR reporting. All patients who initiated dialysis between January of 2001 and December of 2010 in four Canadian provinces that implemented province-wide automated eGFR reporting and had an eGFR measure at dialysis initiation were included in the study (n=22,208). The primary outcome was change over time in eGFR among patients at dialysis initiation. An interrupted time series and adjusted multilevel regression models were used to determine the differences in eGFR at dialysis initiation before and after reporting. We observed a linear increase in the mean eGFR at dialysis initiation from 9.1 to 10.8 ml/min per m(2) during the study period. There was no change in the trajectory of the eGFR at dialysis initiation before or after eGFR reporting in crude or adjusted models accounting for case mix and facility characteristics. These findings were consistent among age and sex strata and when the proportions of patients with an eGFR≥10.5 or ≥12 ml/min per m(2) were examined. In conclusion, automated laboratory-based eGFR reporting did not influence eGFR at dialysis initiation among incident dialysis patient populations. Concerns that widespread eGFR reporting leads to earlier dialysis initiation are not supported by this study.

Figure 1.

Unadjusted interrupted time series of (A) mean eGFR, (B) proportion of patients initiated with an eGFR≥10.5 ml/min per m², and (C) proportion of patients initiated dialysis with an eGFR≥12 ml/min per m² before and after eGFR reporting. Each point represents the mean or proportion among incident dialysis patients in that 3-month period. Gray bars represent the 6-month transition periods. The solid line represents the linear trend line. Significance testing for the change in slope and the change in intercept: mean eGFR: P(slope)=0.66, P(intercept)=0.66; eGFR≥10.5 ml/min per m²: P(slope)=0.18, P(intercept)=0.47; eGFR≥12 ml/mi per m²: P(slope)=0.47, P(intercept)=0.57.