Table 1. Multivariable regression analysis for potential confounding effects.

Parameter	Regression coefficient	95% confidence interval	p-value
Intercept	0.028	[-1.759, 1.815]	0.976
Anemia with IV iron	-0.595	[-1.144, -0.047]	0.033
Anemia without IV iron	Reference	-	-
Number of days	0.026	[0.008, 0.044]	0.006
Gender (female)	0.28	[-0.291, 0.85]	0.337
Gender (male)	Reference	-	-
Age [years]	0.002	[-0.023, 0.026]	0.901

Table 1 shows the results of a multivariable regression analysis, in which the effect of IV iron on Hgb levels has been analyzed adjusted for the potential confounding factors a) number of days, b) age of the patients and c) gender.