Table 1.

Characteristics of study population (n = 18,454)^a

Characteristic	Value
Patient demographics
race (%)
white	69.4
black	25.3
other/unknown	5.3
age (yr; mean)	75.7
male gender (%)	51.2
Facility characteristics
region (%)
Northeast (networks 1 to 5)	24.0
Southeast (networks 6 to 8, 13, 14)	35.4
Midwest (networks 9 to 12)	23.9
West (networks 15 to 18)	16.6
chain membership (%)
chain 1	30.6
chain 2	14.1
chain 3	15.1
chain 4	8.8
chain 5	3.8
chain 6	2.2
small chain/nonchain	25.4
Patient clinical history (%)
cause of ESRD
diabetes	46.9
hypertension	36.1
glomerulonephritis	5.1
cystic kidney	1.0
other	10.9
body weight (kg)
<61	23.9
61 to <72	25.7
72 to 84	24.3
≥84	26.2
Charlson index scoreb
<3	18.2
3 to <6	29.4
6 to <8	21.0
≥8	31.4
baseline hospitalization (d)b
0	56.1
<5	11.4
5 to <10	12.8
≥10	19.7
cardiovascular comorbidities (% yes)	63.1
noncardiovascular comorbidities (% yes)	61.4
Anemia management practices
receipt of predialysis epoetin (% yes)	35.1
hematocrit level at end of month 3 (%)
<30	6.5
30 to <33	10.5
33 to <36	20.1
36 to <39	27.6
≥39	35.3
epoetin dosage administered (U/wk)b
<10,000	9.8
10,000 to <20,000	34.5
20,000 to <30,000	30.5
30,000 to <40,000	14.5
≥40,000	10.6
Average iron administered (mg/mo)b
<450	20.2
450 to <800	19.4
800 to <1200	24.6
≥1200	35.8

^aAll variables in Table 1 were adjusted for in the survival analyses. Unless otherwise noted, all variables were collected at study entry.

^bFirst 3 mo of dialysis therapy.