Table 4.

Multivariate logistic regression analysis of factors associated with anemia (hematocrit < 33%) at the time of enrollment^a

Variable	Odds Ratio	95% Confidence Interval
CKD stage
V	8.50	4.51 to 16.00b
IV	4.83	3.37 to 6.92b
III	1.89	1.39 to 2.56b
II	1.00	—
Weight z-score	0.88	0.82 to 0.93c
Primary diagnosis
dysplasia	0.93	0.66 to 1.30
reflux nephropathy	1.09	0.73 to 1.62
FSGS	1.00	0.62 to 1.59
other	2.05	1.56 to 2.70b
obstructive uropathy	1.00	—
Iron supplementation
yes	2.39	1.85 to 3.08b
no	1.00	—
Erythropoietin use
yes	0.70	0.50 to 0.97d
no	1.00	—
Serum calcium
high	0.50	0.38 to 0.66b
low	1.31	0.85 to 2.03
normal	1.00	—
Serum phosphorus
high	1.82	1.41 to 2.35b
normal	1.00	—
Parathyroid hormone level
>2× upper limit of normal	2.14	1.61 to 2.83b
unknown	1.29	1.02 to 1.63d
<2× upper limit of normal	1.00	—
Age (yr)
2 to 5	1.84	1.34 to 2.54c
6 to 12	1.81	1.40 to 2.34b
>12	1.00	—
Antihypertensive medication use
yes	1.27	1.02 to 1.59d
no	1.00	—
Cohort year
1994 to 1997	1.43	1.14 to 1.79c
1998 to 2004	1.00	—
Albumin	0.48	0.40 to 0.57b

^aFactors included in the multivariate analysis include: age, race, gender, primary diagnosis, cohort year, height z-score, weight z-score, parathyroid hormone, calcium, phosphorus, CKD stage, albumin, antihypertensive medication use, iron supplementation, growth hormone use, and erythropoietin use.

^bP value < 0.0001;

^cP value < 0.005;

^dP value < 0.05.