Table 3.

Association of hemoglobinopathy trait with being in the highest quartile of ESA dosing

Covariate	Univariable Analysis OR (95% CI)	P Value	Multivariable Analysis OR (95% CI)	P Value	Simplified Analysisa OR (95% CI)	P Value
Any Hb trait	1.25 (1.03 to 1.50)	0.02	1.44 (1.17 to 1.77)	0.001	1.30 (1.07 to 1.58)	0.01
Age (yr)	0.98 (0.98 to 0.99)	<0.001	0.98 (0.98 to 0.99)	<0.001
Sex (men)	0.91 (0.80 to 1.04)	0.17	0.91 (0.78 to 1.05)	0.20
Dialysis vintage (yr)	1.00 (1.00 to 1.00)b	0.65	1.00 (1.00 to 1.00)b	0.001
Intact parathyroid hormone	1.00 (1.00 to 1.00)b	<0.001	1.00 (1.00 to 1.00)b	<0.001
Albumin	0.20 (0.17 to 0.24)	<0.001	0.21 (0.17 to 0.27)	<0.001
Kt/V	0.16 (0.11 to 0.22)	<0.001	0.34 (0.23 to 0.51)	<0.001
Ferritin	1.00 (1.00 to 1.00)b	<0.001	1.00 (1.00 to 1.00)b	<0.001
Transferrin saturation	0.92 (0.91 to 0.93)	<0.001	0.94 (0.93 to 0.95)	<0.001	0.92 (0.91 to 0.93)	<0.001
Access type (catheter versus AVF/AVG)	2.11 (1.84 to 2.41)	<0.001	1.27 (1.08 to 1.48)	0.003
Iron dose	1.10 (1.08 to 1.12)	<0.001	1.04 (1.02 to 1.06)	<0.001
Missed treatments	1.04 (1.03 to 1.05)	<0.001	1.03 (1.02 to 1.04)	<0.001
Hospitalization days			2.20 (1.50 to 3.23)	<0.001
Model stratified by trait typec
HbAS	1.22 (0.99 to 1.49)	0.06	1.44 (1.14 to 1.80)	0.002	1.27 (1.03 to 1.57)	0.03
HbAC	1.38 (0.93 to 2.04)	0.11	1.44 (0.93 to 2.22)	0.10	1.43 (0.95 to 2.17)	0.09

Any Hb trait, any hemoglobinopathy trait (includes HbAS and HbAC).

^aSimplified logistic regression model or final model—derived from full model with removal of covariates by backward elimination by change in estimate testing—adjusted for transferrin saturation only.

^bOnly reported to two significant digits but may be < or >1.00.

^cCovariates and their ORs (95% CIs) identical to the model using any Hb trait as primary exposure.