Relationship between Preoperative Hemoglobin and Hospital Stays in Patients Receiving Prime Total Knee Arthroplasty

Table 2

Variables that predict increased LOS in hospital after primary unilateral total knee replacement, based on univariate and multivariate analyses.

Variable	OR (95%CI)	value	OR (95%CI)	value
Age	1.0 (1.0 to 1.1)	<0.001	1.0 (1.0 to 1.1)	<0.001
BMI
<25	REF		REF
≥25, <30	1.0 (0.7 to 1.3)	0.857	1.0 (0.8 to 1.4)	0.797
≥30, <35	0.8 (0.6 to 1.1)	0.168	0.9 (0.6 to 1.3)	0.507
≥35	1.3 (0.8 to 2.0)	0.292	1.6 (1.0 to 2.7)	0.068
Race
Chinese	REF		REF
Malay	0.7 (0.4 to 1.1)	0.109	0.6 (0.3 to 1.1)	0.082
Indian	1.4 (0.9 to 2.1)	0.139	1.4 (0.9 to 2.2)	0.167
Gender
Female	REF		REF
Male	0.9 (0.7 to 1.1)	0.311	0.9 (0.7 to 1.3)	0.684
Type of anesthesia
RA	REF		REF
GA	1.3 (1.0 to 1.6)	0.052	1.4 (1.1 to 1.8)	0.005
GA RA	1.4 (0.5 to 3.7)	0.541	1.5 (0.5 to 4.1)	0.479
Operation duration (min)	1.0 (1.0 to 1.0)	<0.001	1.0 (1.0 to 1.0)	0.005
Day of week of op
Thursday	REF		REF
Tuesday	2.1 (1.5 to 3.0)	<0.001	2.4 (1.7 to 3.5)	<0.001
Wednesday	2.0 (1.3 to 2.9)	<0.001	2.0 (1.3 to 3.0)	<0.001
Monday	2.2 (1.5 to 3.2)	<0.001	2.1 (1.4 to 3.2)	<0.001
Friday	2.1 (1.4 to 3.1)	<0.001	1.9 (1.3 to 2.9)	0.001
Saturday	1.2 (0.7 to 2.3)	0.474	1.4 (0.7 to 2.7)	0.286
HB
<11	REF		REF	REF
≥11, <13	0.5 (0.3, to 0.8)	0.002	0.5 (0.3 to 0.8)	0.001
≥13	0.4 (0.2, 0.6)	<0.001	0.4 (0.2, 0.6)	<0.001
Smoking
No	REF		REF
Yes	1.0 (0.7 to 1.5)	0.897	1.1 (0.7 to 1.7)	0.725
DM
No	REF		REF
Yes	1.5 (1.2 to 2.0)	0.001	1.4 (1.0 to 1.8)	0.032
IHD
No	REF		REF
Yes	1.6 (1.1 to 2.5)	0.026	1.3 (0.8 to 2.2)	0.238
CCF
No	REF		REF
Yes	1.4 (0.4 to 5.2)	0.585	1.4 (0.3 to 5.4)	0.671
CVA
No	REF		REF
Yes	3.8 (2.0 to 6.9)	<0.001	3.0 (1.6 to 5.9)	<0.001
Creatinine >2 mg/dL
No	REF		REF
Yes	2.2 (0.7 to 7.1)	0.202	1.9 (0.5 to 6.9)	0.313
DM on insulin
No	REF		REF
Yes	1.2 (0.5 to 2.7)	0.721	1.1 (0.5 to 2.8)	0.782