Table 1 Characteristics of included studies for COMP

Clark1999

Control

148

60 ± 20

144

USA

K-L 0 = 148, K-L2 = 109

K-L 3,4 = 34

In-house method

Competitive

OA

143

60 ± 20

Das Gupta E2017

Control

30

62.5 ± 12

15

25.01 ± 6.31

Malaysia

K-L 2 = 30

K-L 3 = 23

K-L 4 = 7

R&D Systems

Solid-phase sandwich

OA

60

57.5 ± 9

46

26.72 ± 5.35

Fernandes2007

Control

40

53.8 ± 8.5

24

Brazil

K-L 0,1 = 40

K-L 2–4 = 75

AnaMar Medical (Uppsala, Sweden)

Sandwich

OA

75

56.6 ± 7.6

51

Jordan JM2003

Control

302

63.3 ± 10.8

258

31.5 ± 7.4

USA

K-L 0 = 302, K-L 2 = 313, K-L 3 = 110, K-L 4 = 44

AnaMar Medical (Lund, Sweden)

Sandwich

OA

467

60.6 ± 9.6

190

28.9 ± 6.1

Li2012

Control

35

53 ± 12.53

19

21.8 ± 4.9

China

K-L 1 = 28, K-L 2 = 36, K-L 3 = 27, K-L 4 = 24

AnaMar Medical AB (Lund, Sweden)

Sandwich

OA

115

55 ± 13.32

60

22.3 ± 5.7

Mündermann A2009

Control

41

57.5 ± 7

20

25.7 ± 4.2

USA

K-L 1 = 11, K-L 2 = 7, K-L 3 = 12, K-L 4 = 12

AnaMar Medical AB (Lund, Sweden)

Sandwich

OA

42

60.7 ± 8.6

22

27.0 ± 3.8

Author

Group

N

Age (years)

Female (n)

BMI (kg/m2)

Region

K-L 0~4 of patients (n)

ELISA manufacture information

Type of ELISA

Senolt L2005

Control

38

58.3 ± 9.1

23

Czech Republic

K-L 1 = 2, K-L 2 = 18

K-L 3 = 14, K-L 4 = 4

In-house method

Sandwich

OA

38

64.1 ± 10.1

25

Sowers MF2009

Control

36

47.5 ± 2.6

36

29.7 ± 6.2

France

K-L 0,1 = 36

K-L 2 = 16

K-L 3,4 = 20

AnaMar Medical (COMPTM ELISA kit)

A two-site ELISA

OA

36

47.5 ± 2.6

36

39.15 ± 8.22

Wakitani2007

Control

24

20–54

8

Japan

K-L 1 = 7, K-L 2 = 4

K-L 3 = 6, K-L 4 = 7

Kamiya Biomedical

Company, Seattle, WA, USA

Sandwich

OA