Table 3

Disease and demographic characteristics of patients based on the status of protective antibody levels at 1

Patients with protective antibody levels at 1.5 years of follow-up

(n = 132)

Patients without protective antibody levels at 1.5 years of follow-up

(n = 170)

P value


Age (years); mean (SD) (range)

51.7 (13) (24-79)

60.1 (11) (30-85)

P < 0.001a


Patient age ≥65 years (%)

16%

37%

P < 0.001b


Gender (female %)

58%

72%

P = 0.01b


Disease duration (years); mean (SD) (range)

13.8 (10) (0-45)

16.7 (11) (0-46)

P = 0.039a


DAS at vaccination; mean (SD) (range)

3.0 (1.3) (0-5.6)

3.5 (1) (0-6.4)

P = 0.001a


HAQ at vaccination; mean (SD) (range)

0.6 (0.5) (0-2)

0.9 (0.7) (0-3)

P < 0.001a


RA (yes, %)

38/62

66/34

P < 0.001b


Ongoing MTX (yes, %)

44%

61%

P < 0.001b


Ongoing anti-TNF treatment (yes, %)

60%

72%

P = 0.029b


Positive antibody response for 6B and 23F at 4 to 6 weeks of follow-up (yes, %)

37.1%

25%

P = 0.027b


Protective antibody levels for both 6B and 23F serotypes at vaccination (%)

72%

20.6%

P < 0.001b


aMann-Whitney U test. bχ2 test.

Crnkic Kapetanovic et al. Arthritis Research & Therapy 2013 15:R1   doi:10.1186/ar4127

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