Table 3.

Associations between participant characteristics and ERI by univariate multinomial logistic regression

Variable	Coefficient	95 % confidence intervals	P value
Women (Reference men)	−0.83	−2.19 to 0.53	0.2
Non-Caucasians (Reference Caucasians)	0.76	−1.08 to 2.61	0.4
Diabetes mellitus (Reference non-diabetics)	0.85	−0.68 to 2.38	0.3
Cause of kidney disease
Diabetes	Reference
Glomerulonephritis	−1.16	−3.19 to 0.87	0.3
Analgesic nephropathy	NR	NR	NR
Polycystic kidney disease	−0.47	−3.46 to 2.52	0.8
Reflux nephropathy	−0.47	−3.46 to 2.52	0.8
Renovascular disease	NR	NR	NR
Others	−0.29	−1.92 to 1.34	0.7
Smoking status
Never	Reference
Former	0.47	−0.98 to 1.92	0.5
Current	−1.10	−3.54 to 1.35	0.4
Body mass index category
Healthy weight	Reference
Overweight	1.28	−0.48 to 3.05	0.2
Obese	−0.51	−2.20 to 1.18	0.6
Ischemic heart disease	−0.28	−1.78 to 1.20	0.7
Congestive heart failure	−1.40	−3.26 to 0.46	0.1
Age	0.03	−0.01 to 0.08	0.2
Reticulocyte count	−0.01	−0.03 to 0.02	0.5
Total white cell count	0.03	−0.33 to 0.40	0.9
Ferritina	0.01	−0.09 to 0.11	0.8
Transferrin saturationb	0.05	−2.29 to 2.39	0.9
Albumin	0.06	−0.09 to 0.21	0.4
Alkaline phosphatasec	44.01	7.63 to 80.40	0.02
Gamma-glutamyltransferaseb	−0.65	−1.60 to 0.30	0.2
Alanine transaminasec	−7.42	−16.80 to 1.96	0.1
Aspartate transaminasec	−8.50	−20.62 to 3.62	0.2
Lactate dehydrogenaseb	−2.18	−5.06 to 0.69	0.1
Albumin-corrected calcium	3.46	−0.60 to 7.51	0.09
Phosphate	−0.01	−1.31 to 1.29	0.9
Parathyroid hormonea	−0.25	−0.55 to 0.05	0.1
C-reactive protein	−0.03	−0.08 to 0.01	0.2
Total F2-isoprostanesb	0.36	−0.69 to 1.42	0.5
Glutathione peroxidise activityd	NR	NR	NR
Superoxide dismutase activitye	1.49	−1.91 to 4.90	0.4
Protein carbonylse	0.24	−1.26 to 1.74	0.8

NR Estimates could not be obtained due to small number of patients

The following non-normally distributed variables were transformed to normality of distribution:

^asquare root

^blog-transformed

^creciprocal of square root

^dpower of 3

^e reciprocal