Table 1.

Clinical characteristics of the study population in the 2016–2018 KURAMA cohort

n = 224	2016	2017	2018
The positivity of anti-cit-OPN antibody, %	44.2	43.3	45.5
The positive rate of anti-cit-OPN antibody in anti-CCP antibody-positive patients, %	53.5	50.9	52.4
DAS28-CRP	2.09 ± 0.81	2.10 ± 0.81	1.94 ± 0.73
DAS28-ESR	2.64 ± 0.96	2.66 ± 0.99	2.43 ± 0.97
Anti-CCP antibody, U/mL	266.0 ± 444.7	355.6 ± 566.3	403.5 ± 772.1
The rate of anti-CCP antibody positive, %	77.8	77.7	78.0
Rheumatoid factor, IU/mL	119.7 ± 240.4	120.6 ± 264.4	130.1 ± 296.0
The rate of rheumatoid factor positive, %	77.7	80.0	78.6
CRP, mg/dL	0.36 ± 0.74	0.36 ± 0.64	0.38 ± 0.73
ESR 1 h, mm/h	20.6 ± 16.3	21.1 ± 16.7	20.3 ± 17.6
ptVAS, 0–100 mm	22.3 ± 21.8	22.9 ± 21.8	23.0 ± 22.6
The use of PSL, %	22.8	22.3	22.3
PSL dose, mg/day	3.78 ± 4.16	3.29 ± 2.10	3.31 ± 1.73
The use of MTX, %	75.0	74.6	73.7
MTX dose, mg/week	7.37 ± 3.13	7.50 ± 3.16	7.47 ± 3.28
The use of biologic DMARDs, %	50.9	52.2	54.5

CRP C-reactive protein, C reactive protein, ESR Erythrocyte sedimentation rate, CCP Cyclic citrullinated peptide, VAS Visual analog scale, PSL Prednisolone, MTX Methotrexate, DMARDs Disease-modifying anti-rheumatic drugs