Trends in timing of initiation of chronic dialysis in the United States

Abstract

Background: During the past decade, a trend has been observed in the United States toward initiation of chronic dialysis at higher levels of estimated glomerular filtration rate. This likely reflects secular trends in the composition of the dialysis population and a tendency toward initiation of dialysis earlier in the course of kidney disease.

Methods: The goal of this study was to generate model-based estimates of the magnitude of changes in the timing of dialysis initiation between 1997 and 2007. We used information from a national registry for end-stage renal disease on estimated glomerular filtration rate at initiation among patients who received their first chronic dialysis treatment in 1997 or 2007. We used information regarding predialysis estimated glomerular filtration rate slope from an integrated health care system.

Results: After accounting for changes in the characteristics of new US dialysis patients from 1997 to 2007, we estimate that chronic dialysis was initiated a mean of 147 days earlier (95% confidence interval, 134-160) in the later compared with the earlier year. Differences in timing were consistent across a range of patient subgroups but were most pronounced for those aged 75 years or older; the mean difference in timing in that subgroup was 233 days (95% confidence interval, 206-267).

Conclusions: Chronic dialysis appears to have been initiated substantially earlier in the course of kidney disease in 2007 compared with 1997. In the absence of strong evidence to suggest that earlier initiation of chronic dialysis is beneficial, these findings call for careful evaluation of contemporary dialysis initiation practices in the United States.

Figure 1.

Schematic to illustrate the relationship between level of renal function at dialysis initiation, loss of renal function prior to initiation, and timing of initiation in a hypothetical patient. A, Difference between each patient’s level of renal function at initiation of dialysis in 2007 and a prediction of the level of renal function at which he or she would have initiated dialysis based on 1997 practice (estimated glomerular filtration rate [eGFR]₂₀₀₇−eGFR₁₉₉₇). B, Prediction of how rapidly each patient was losing renal function prior to dialysis initiation (chronic outpatient eGFR slope before dialysis initiation [SLOPE_eGFR]). C, A (difference in eGFR in mL/min/1.73 m²)/B (rate of eGFR loss in mL/min/1.73 m²/day)=number of days earlier patients initiated dialysis in 2007 compared with when they would have initiated dialysis based on 1997 practice.

Figure 2.

Mean number of days earlier that patients initiated dialysis in 2007 compared with 1997.