Table 3.

Characteristics of patients receiving elective orthopedic surgery after 1:1 propensity score matching

	After propensity score matching
	Normal liver enzyme level (N = 29,189)		Elevated liver enzyme level (N = 29,189)
Characteristics	N (%)		N (%)		SMD
Demographics
Age, years
< 65	17,224	(59.0)	17,162	(58.8)	0.004
65–74	8075	(27.7)	8078	(27.7)	< 0.001
75–84	3126	(10.7)	3149	(10.8)	0.002
≥ 85	764	(2.6)	800	(2.7)	0.007
Sex
Female	13,893	(47.6)	13,904	(47.6)	0.001
Male	15,296	(52.4)	15,285	(52.4)	0.001
Functional status
Independent	28,243	(97.1)	28,296	(96.9)	0.010
Dependent	846	(2.9)	893	(3.1)	0.010
Obesity	16,519	(56.6)	16,483	(56.5)	0.002
Smoking	5202	(17.8)	5139	(17.6)	0.006
Comorbidities
Steroid use	1403	(4.8)	1393	(4.8)	0.002
Ascites	40	(0.1)	55	(0.2)	0.015
Ventilator dependent	16	(0.1)	29	(0.1)	0.018
Disseminated cancer	373	(1.3)	389	(1.3)	0.006
Diabetes mellitus	6201	(21.2)	6172	(21.1)	0.003
Hypertension	18,275	(62.6)	18,278	(62.6)	< 0.001
Congestive heart failure	182	(0.6)	219	(0.8)	0.016
COPD	1514	(5.2)	1509	(5.2)	0.001
Dialysis	111	(0.4)	122	(0.4)	0.006
Sepsis	491	(1.7)	525	(1.8)	0.011
Operative information
Type of surgery
Limb amputation	216	(0.7)	236	(0.8)	0.009
Spinal fusion	2325	(8.0)	2301	(7.9)	0.003
Open reduction of fracture	3529	(12.1)	3498	(12.0)	0.004
Hip prosthesis	8966	(30.0)	8810	(30.2)	0.003
Knee prosthesis	12,521	(42.9)	12,510	(42.9)	0.001
Laminectomy	1832	(6.3)	1834	(6.3)	< 0.001
ASA classification	10,254	(42.1)
1	535	(1.8)	542	(1.9)	0.002
2	11,817	(40.5)	11,801	(40.4)	0.001
3	15,759	(54.0)	15,697	(53.8)	0.004
4 or 5	1078	(3.7)	1149	(3.9)	0.014

COPD chronic obstructive pulmonary disease