Table 1 Characteristics of patients before and after propensity score matching

n

228,595

30,724

30,591

30,591

Sex

Men

47,839 (20.9%)

8487 (27.6%)

0.16

< 0.0001*

7932 (26.0%)

8459 (27.6%)

0.039

< 0.0001*

Women

180,756 (79.1%)

22,237 (72.4%)

22,659 (74.0%)

22,132 (72.4%)

Age (years)

74.8 ± 7.8

74.3 ± 7.6

0.056

< 0.0001*

74.4 ± 7.7

74.3 ± 7.6

0.009

0.28

Body mass index

26.2 ± 4.9

25.3 ± 3.6

0.19

< 0.0001*

25.2 ± 3.8

25.3 ± 3.6

0.012

0.13

Hypertension

81,559 (35.7%)

9894 (32.2%)

0.073

< 0.0001*

9573 (31.3%)

9861 (32.2%)

0.02

0.012

Diabetes

49,373 (21.6%)

5801 (18.9%)

0.068

< 0.0001*

5420 (17.7%)

5783 (18.9%)

0.031

0.0001*

Cerebrovascular disease

7419 (3.3%)

879 (2.9%)

0.022

0.0003*

804 (2.6%)

877 (2.9%)

0.015

0.071

Ischemic heart disease

13,615 (6.0%)

1671 (5.4%)

0.022

0.0003*

1545 (5.0%)

1663 (5.4%)

0.017

0.032

Chronic renal dysfunction

6438 (2.8%)

698 (2.3%)

0.035

< 0.0001*

603 (2.0%)

696 (2.3%)

0.021

0.009*

Chronic lung disease

1350 (0.6%)

137 (0.5%)

0.02

0.0016*

117 (0.4%)

137 (0.4%)

0.01

0.21

Cognitive impairment

3594 (1.6%)

373 (1.2%)

0.031

< 0.0001*

345 (1.1%)

372 (1.2%)

0.008

0.31

Hyperlipidemia

45,250 (19.8%)

6087 (19.8%)

0.0004

0.94

5728 (18.7%)

6053 (19.8%)

0.027

0.0009*

Rheumatic disease

9105 (4.0%)

394 (1.3%)

0.18

< 0.0001*

423 (1.4%)

391 (1.3%)

0.009

0.26

Bilateral surgery

15,375 (6.7%)

1275 (4.2%)

0.11

< 0.0001*

1094 (3.6%)

1274 (4.2%)

0.03

0.0002*

Non-covariate

TKA

UKA

F value or χ² statistics

p-value

TKA

UKA

F value or χ² statistics

p-value

Charlson Comorbidity Index

0.70 ± 0.95

0.54 ± 0.85

850.7

< 0.0001*

0.61 ± 0.89

0.54 ± 0.85

101.7

< 0.0001*

Glucocorticoid use

6136 (2.7%)

341 (1.1%)

275.6

< 0.0001*

715 (2.3%)

340 (1.1%)

135.6

< 0.0001*

Length of hospitalization (days)

28.6 ± 15.9

22.9 ± 11.5

3666

< 0.0001*

28.3 ± 14.7

22.9 ± 11.5

2515

< 0.0001*

Mortality during hospitalization

104 (0.05%)

10 (0.03%)

1.0

0.31

15 (0.05%)

10 (0.03%)

1.0

0.32

Blood transfusion day 0 (unit)

0.06 ± 0.42

0.006 ± 0.12

531.0

< 0.0001*

0.05 ± 0.40

0.006 ± 0.12

425.5

< 0.0001*

Blood transfusion day 1 (unit)

0.04 ± 0.30

0.002 ± 0.07

395.6

< 0.0001*

0.03 ± 0.28

0.002 ± 0.07

332.7

< 0.0001*

Bone cement use

206,532 (90.4%)

29,003 (94.4%)

533.3

< 0.0001*

27,721 (90.6%)

28,874 (94.4%)

313.3

< 0.0001*

Navigation use

65,889 (28.8%)

8096 (26.4%)

81.2

< 0.0001*

8807 (28.8%)

8058 (26.3%)

45.9

< 0.0001*