The ideal timing of initiation of renal replacement (RRT) therapy has been
debated. It is currently recommended that RRT be instituted once the GFR fa
lls below 10.5 ml/min per 1.73m(2), unless edema-free body weight is stable
or increased, the normalized protein nitrogen appearance rate is 0.8 g/kg
per d or greater, and there are no clinical signs or symptoms of uremia. Ho
wever, the mean estimated GFR at initiation of dialysis in the United State
s is 7.1 ml/min per 1.73m(2). Factors that are associated with timing of in
itiation of dialysis in the United States are not clear. A cross-sectional
study was performed to determine the factors that are associated with late
initiation of dialysis as defined by GFR at initiation of less than 5 ml/mi
n per 1.73m(2) among patients who began dialysis in the United States betwe
en 1995 and 1997. Data were obtained from the U.S. Renal Data System, and G
FR was estimated using the formula derived from the Modification of Diet in
Renal Disease Study. Twenty-three percent of patients started dialysis lat
e. In the multivariate analysis, women (odds ratio [OR] = 1.70), Hispanics
and Asians (OR = 1.47 and 1.66, respectively, compared with Caucasians), un
insured patients (OR = 1.55 compared with private insurance), and employed
patients (OR = 1.20) were more likely to start dialysis late. Patients with
diabetes, cardiac disease, peripheral vascular disease, and poor functiona
l status were less likely to start dialysis late compared with patients wit
hout these comorbid conditions. Certain nonclinical patient characteristics
, notably female gender, race, and lack of insurance, are related to an inc
reased likelihood of late initiation of dialysis. These factors may reflect
reduced access to care. Additional studies are indicated to determine the
potential impact of reduced access to care and whether late initiation of d
ialysis results in adverse clinical and economic outcomes among patients wi
th end-stage renal disease in the United States.