Table 1. Demographic Data by Albumin Class.

Variable	Preoperative serum albumin				p-value
	< 3.5 g/dL	3.5–4.0 g/dL	4.0–4.5 g/dL	> 4.5 g/dL
No. of patients	114 (3.0)	707 (18.7)	2,043 (54.0)	921 (24.3)
Age (yr)	62.5 ± 12.4	63.9 ± 11.2	62.9 ± 10.5	60.1 ± 10.9	< 0.001*
Hemoglobin (g/dL)	11.3 ± 1.7	12.3 ± 1.5	13.2 ± 1.4	13.8 ± 1.4	< 0.001*
BMI (kg/m2)	33.9 ± 8.5	34.8 ± 8.5	33.1 ± 7.6	31.5 ± 6.6	< 0.001*
Cirrhosis	19 (17.3)	16 (2.3)	12 (0.6)	5 (0.6)	< 0.001*
Type of procedure
Primary	83 (72.8)	582 (82.3)	1,826 (89.4)	841 (91.3)	< 0.001*
Revision	31 (27.2)	125 (17.7)	217 (10.6)	80 (8.7)	< 0.001*
Joint
Hip	36 (31.6)	213 (30.1)	671 (32.8)	323 (35.1)	0.211
Knee	78 (68.4)	494 (70.0)	1,372 (67.2)	598 (64.9)	0.211
Procedure type
Primary TKA	57 (50.0)	417 (59.0)	1,222 (59.8)	545 (59.2)	0.228
Revision TKA	21 (18.4)	77 (10.9)	150 (7.3)	53 (5.8)	< 0.001*
Primary THA	26 (22.8)	165 (23.3)	604 (29.6)	296 (32.1)	< 0.001*
Revision THA	10 (8.8)	48 (6.8)	67 (3.3)	27 (2.9)	< 0.001*
LOS (day)	4.4 ± 2.9	3.5 ± 2.4	3.0 ± 1.5	2.8 ± 1.2	< 0.001*
Primary	4.1 ± 2.5	3.4 ± 2.5	3.0 ± 1.4	2.8 ± 1.2	< 0.001*
Revision	5.3 ± 3.6	4.1 ± 1.7	3.6 ± 2.2	3.0 ± 1.5	< 0.001*
Total cost ($)	20,138 ± 10,322	16,045 ± 6,950	14,395 ± 5,784	13,968 ± 5,611	< 0.001*
Primary	17,790 ± 9,402	14,072 ± 4,737	13,473 ± 5,784	13,482 ± 5,040	< 0.001*
Revision	26,426 ± 10,178	25,228 ± 8,163	22,153 ± 9,570	19,080 ± 8,224	< 0.001*
Total readmission	9 (7.9)	53 (7.5)	79 (3.9)	22 (2.4)	< 0.001*
Primary	7 (8.4)	39 (6.7)	66 (3.6)	20 (2.4)	< 0.001*
Revision	2 (6.4)	14 (11.2)	13 (6.0)	2 (2.5)	< 0.001*

Values are presented as number (%) or mean ± standard deviation.

BMI: body mass index, TKA: total knee arthroplasty, THA: total hip arthroplasty, LOS: length of stay.

^*Statistical significance.