Table 4.

Linear regression analysis of the association between change in hematocrit levels and hemoglobin concentration with demographics, duration of surgery and method of TKA (i.e. conventional or with navigation).

Multivariate analysis	Change in hematocrit				Change in hemoglobulin
	R2	β	95% CI	p-Value	R2	β	95% CI	p-Value
BMI	0.02	−0.33	[− 0.43, 0.81]	0.22	0.02	−0.13	[− 0.17, 0.19]	0.15
Sex	0.25	0.51	[ − 0.32, 1.05]	0.06	0.25	0.21	[ − 0.03, 1.03]	0.07
TKA method	0.03	0.37	[ − 0.10, 0.88]	0.08	0.01	0.13	[ − 0.20, 1.25]	0.23
Age	0.01	0.42	[− 0.27, 1.12]	0.23	0.01	0.54	[− 0.37, 1.24]	0.22
Duration	0.29	−0.43	[− 0.48, −0.40]	0.003	0.28	−0.10	[− 0.12, −0.02]	0.004
CCI	0.03	−0.23	[− 0.11, 0.24]	0.08	0.03	−0.08	[− 0.16, 0.01]	0.07

Abbreviations: TKA, total knee arthroplasty; BMI, body mass index; CCI, Charlson comorbidity index.