Table 1.

Baseline characteristics of the study population at the time of ESRD (HD initiation)

CharacteristicEntire Study Population (n=115,425)Access Type: Fistula (n=21,436)Access Type: Graft (n=3472)Access Type: Catheter (n=90,517)P Value
Age at ESRD onset, yr
Mean (SD)76.9 (6.4)76.2 (6.0)76.2 (6.0)77.2 (6.5)<0.001
Median (interquartile range)77 (10)76 (10)76 (10)77 (10)
Age categories (yr), %<0.001
 67–79 (n=74,997)6569.769.563.7
 80–89 (n=37,149)32.228.929.133.1
 >90 (n=3279)2.81.41.43.2
Race, %<0.001
 White75.577.862.275.5
 Black20.318.133.220.3
 Native American0.70.80.60.6
 Asian3.53.33.93.5
 Other0.10.040.10.1
Sex, %<0.001
 Woman47.141.657.348
 Man52.958.442.752
BMI (kg/m2)27.3 (6.8)27.9 (6.5)28.0 (6.9)27.1 (6.8)<0.001
BMI categories (kg/m2)
 Underweight (<18.5)6.04.14.86.5<0.001
 Normal (18.5–24.9)36.032.433.237.0
 Overweight (25–29.9)30.733.430.230.0
 Obese (≥30)27.330.131.826.5
Comorbidity index8.3 (1.6)8.1 (1.5)8.2 (1.5)8.3 (1.6)<0.001
Diabetes, %<0.001
 Yes55.156.259.954.6
 No44.943.840.145.4
Malignancy, %<0.001
 Yes11.410.41011.7
 No88.689.69088.3
PVD, %<0.001
 Yes18.318.217.618.3
 No81.781.882.481.7
Duration of pre-ESRD nephrology care, %<0.001
 No care31.15.66.738.1
 0–6 months10.713.7139.9
 6–12 months22.129.131.120.1
 >12 months22.745.742.816.5
 Missing13.35.86.415.4
Primary cause of ESRD, %<0.001
 Diabetes40.744.848.439.4
 GN4.15.74.53.8
 Hypertension36.437.33736.1
 Cystic disease0.92.11.40.6
 Other1810.18.620.2
  • Continuous variables are presented as mean (SD), and categorical variables are presented as the percent of total. P values are based on ANOVA test. Nonsignificant P value supports the null hypothesis stating that all group means are equal to each other.