Table 1.

Baseline data of the nonconcurrent (left truncated) cohort of 58,058 MHD patients, including 37,049 from the first quarter (q1) and 21,009 from subsequent quarters (q2 to q8)a

VariableReceived IV Iron at Baselineb (n = 38,569)No IV Iron at Baselineb (n = 19,489)P Value
Age (yr)61 ± 1561 ± 150.7
Gender (% women)46460.06
Diabetes (%)4642<0.001
Race and ethnicity (%)
    white37370.10
    black32310.004
    Hispanic17180.04
3 to 6 mo on dialysis (%)4826<0.001
Medicare (%)5961<0.001
Known causes of death (%)
    cardiovascular52510.09
    infectious11110.6
Standardized mortality ratio0.80 ± 0.230.79 ± 0.23<0.001
Cohort time (d)447 ± 255465 ± 263<0.001
BMI (kg/m2)26.3 ± 6.325.8 ± 5.6<0.001
Kt/V (single pool)1.5 ± 0.31.6 ± 0.3<0.001
nPNA (g/kg per d)1.0 ± 0.21.0 ± 0.2<0.001
Serum albumin (g/dl)3.7 ± 0.43.8 ± 0.4<0.001
    creatinine (mg/dl)8.8 ± 3.39.4 ± 3.3<0.001
    TIBC (mg/dl)203 ± 42200 ± 43<0.001
    ferritin (ng/ml)556 ± 448718 ± 596<0.001
    iron (ng/ml)59 ± 2565 ± 29<0.001
    iron saturation ratio (%)29 ± 1133 ± 13<0.001
    bicarbonate (mEq/L)21.7 ± 2.822.0 ± 2.9<0.001
    phosphorus (mg/dl)5.7 ± 1.55.7 ± 1.6<0.001
    calcium (mg/dl)9.2 ± 0.79.3 ± 0.8<0.001
Blood hemoglobin (g/dl)12.1 ± 1.311.8 ± 1.3<0.001
    WBC (per fl)7.3 ± 2.37.3 ± 2.4<0.001
    lymphocyte (% of total WBC)21 ± 821 ± 8<0.001
Administered EPO
    proportion received EPO (%)9982<0.001
    EPO dose (units/wk)21,560 ± 17,66016,580 ± 30,440<0.001
  • a MHD, maintenance hemodialysis; IV, intravenous; BMI, body mass index; nPNA, normalized protein nitrogen appearance; TIBC, total iron binding capacity; WBC, white blood cell; EPO, recombinant human erythropoietin.

  • b Baseline period of the cohort pertains to the first 3 mo (first calendar quarter of the cohort).