Table 1 Clinical characteristics at initiation of each biologic agent

Age (years)

63.9 ± 13.0

55.5 ± 13.5

56.3 ± 16.3

55.7 ± 15.8

61.2 ± 14.7

52.8 ± 13.5

57.6 ± 14.2

< 0.001

Female sex (%)

81.2

81.7

87.7

85.0

87.3

78.0

80.8

< 0.001

BMI (kg/m²)

21.9 ± 3.7

22.3 ± 4.1

22.3 ± 3.3

21.9 ± 3.7

22.2 ± 3.5

22.3 ± 4.2

22.2 ± 3.9

0.81

Disease duration (years)

9.5 ± 10.3

7.9 ± 9.6

6.8 ± 8.9

9.1 ± 9.0

10.7 ± 10.7

7.4 ± 8.9

9.2 ± 9.2

< 0.001

RF positivity (%)

83.0

75.4

82.2

80.3

77.4

74.5

78.2

0.014

ACPA positivity (%)

84.6

77.4

85.4

84.2

78.9

82.8

82.9

0.036

DAS28-ESR

4.4 ± 1.3

4.1 ± 1.2

4.5 ± 1.5

4.3 ± 1.4

4.1 ± 1.3

4.4 ± 1.6

4.5 ± 1.4

< 0.001

CDAI

16.7 ± 9.8

14.0 ± 9.1

19.6 ± 12.3

15.9 ± 9.4

15.7 ± 10.8

18.6 ± 12.4

17.0 ± 10.1

0.0025

HAQ-DI

1.1 ± 0.8

0.7 ± 0.7

1.2 ± 0.8

0.9 ± 0.8

1.1 ± 0.8

1.1 ± 0.9

1.2 ± 0.8

< 0.001

PSL usage (%)

48.4

36.1

43.4

42.0

42.6

37.2

49.4

< 0.001

PSL dose (mg/day)

3.4 ± 6.9

2.2 ± 4.4

2.4 ± 3.7

2.5 ± 4.1

2.3 ± 3.5

2.2 ± 4.2

3.1 ± 5.3

0.011

MTX usage (%)

47.9

67.0

70.6

41.2

70.8

98.9

52.1

< 0.001

MTX dose (mg/week)

3.9 ± 4.6

6.0 ± 4.9

6.3 ± 4.8

3.3 ± 4.4

6.0 ± 4.7

8.2 ± 2.5

4.4 ± 4.8

< 0.001

1st bio (%)

59.2

69.9

59.0

72.4

45.5

89.4

43.4

< 0.001

2nd bio (%)

22.2

22.9

17.5

20.5

32.1

7.6

32.7

< 0.001

≥ 3rd bio (%)

18.6

7.2

23.5

7.1

22.4

3.0

23.9

< 0.001