Table 3.

Univariate and multivariate linear regression models for 6MWT and MLHFQ.

	Univariate Models			Multivariate Models
	β Coef.	p Value	Adj. R2	β Coef.	p Value	Adj. R2
6-Min Walking Test (6MWT)
vs. iron deficiency (KDOQI)	−39.77	0.003	0.03	−29.66	0.007	0.35
vs. iron deficiency (FAIR-HF)	−37.23	0.002	0.03	−23.35	0.021	0.35
vs. anemia (WHO)	−40.90	<0.001	0.04	−21.10	0.035	0.34
vs. TSAT < 20%	−36.07	0.004	0.03	−28.42	0.006	0.35
vs. sTfR (log)	−29.51	0.056	0.01	−27.09	0.035	0.36
vs. ferritin (log)	3.71	0.55	<0.01	−4.99	0.34	0.34
vs. serum iron (log)	29.06	0.012	0.05	9.77	0.32	0.34
Minnesota Living with Heart Failure Questionnaire (MLHFQ)
vs. iron deficiency (KDOQI)	6.31	0.009	0.01	4.80	0.039	0.11
vs. iron deficiency (FAIR−HF)	4.76	0.032	<0.01	2.69	0.21	0.10
vs. anemia (WHO)	3.78	0.08	<0.01	1.42	0.50	0.10
vs. TSAT < 20%	4.99	0.029	<0.01	3.32	0.13	0.10
vs. sTfR (log)	12.96	<0.001	0.05	7.95	<0.001	0.15
vs. ferritin (log)	−0.58	0.61	<0.01	0.64	0.56	0.10
vs. serum iron (log)	−3.76	0.08	<0.01	−1.50	0.47	0.10

6MWT (6-Min Walking Test), adj. (adjusted), coef. (coefficient), FAIR-HF (Ferinject Assessment in patients with IRon deficiency and chronic Heart Failure study), KDOQI (Kidney Disease Outcomes Quality Initiative), LVEF (left ventricular ejection fraction), MLHFQ (Minnesota Living with Heart Failure Questionnaire), NYHA (New York Heart Association), sTfR (serum soluble transferrin receptor), TSAT (transferrin saturation). Multivariate models adjusted by age, sex, NYHA functional class, and LVEF.