Table 4.

Comparison of derivation and validation cohorts

Characteristic/OutcomeDerivation SampleValidation SamplePa
Patients screened512514
Patients with sufficient data to make/test model449427b
Age (yr; mean ± SD)60 ± 17 (n = 449)63 ± 16 (n = 427)0.06
Gender (male vs. female; % [n/N])56.7 (254/448)57.4 (245/427)0.84
Race/ethnicity (% [n/N])
    white versus other64.8 (282/435)76.1 (324/426)0.0003
    Hispanic (versus non-Hispanic)14.3 (62/435)15.7 (67/426)0.54
Time on HD (mo)n = 379n = 423
    median (q1 to q3)18 (4 to 39)37 (18 to 67)<0.0001
    <3 mo (% [n/N])18.7 (71/379)3.8 (16/421)<0.0001
SQ, not surprised (% [n/N])15.8 (71/449)13.3 (57/427)0.30
Albuminn = 449n = 4270.14
    mean ± SD3.8 ± 0.43.9 ± 0.4
    <3.5 (% [n])14.9 (67)14.5 (62)0.87
PVD (% [n/N])3.3 (15)1.4 (6)0.06
Dementia (% [n/N])19.6 (88/449)22.0 (94/427)0.38
6-Mo survival (%; Kaplan-Meier estimate [95% CI])95 (92 to 97)92 (89 to 95)c
  • a P values are from a t test (age), Wilcoxon rank-sum test (time on HD), log-rank test (6-mo estimated survival), or a χ2 test (all other variables). Only cases used in deriving or validating the model were used for these comparisons.

  • b Number of patients who had information on the SQ, albumin, age, dementia, and PVD and had known 6-mo survival status and were included in either creating the model (derivation sample) or validating the model (validation sample).

  • c The validation sample is still being followed.