Difference of demographic and clinical features or treatment status according to smoking status. Results are percentages or medians (interquartile range) and compared separately for each sex.
| Male, n = 810 | Female, n = 4206 | |||||
|---|---|---|---|---|---|---|
| Never Smokers, n = 162 | Past Smokers, n = 440 | Current Smokers, n = 208 | Never Smokers, n = 3173 | Past Smokers, n = 719 | Current Smokers, n = 314 | |
| Age, yrs | 63.2 (48.6, 72.8) | 65.6 (58.8, 72.1) | 61.6 (54.4, 68.1) † | 62.3 (51.7, 69.6) | 59.2 (50.0, 66.5) | 56.7 (47.5, 64.0) † |
| Disease duration, yrs | 10 (5, 17) | 11 (6, 18) | 10 (5, 16.8) | 13 (6, 20) | 10 (6, 16) | 10.5 (5, 16) † |
| BMI, kg/m2 | 22.9 (21.0, 25.1) | 22.9 (20.9, 24.5) | 22.6 (20.6, 24.6) | 20.7 (19.1, 22.6) | 20.8 (19.1, 23.1) | 20.5 (18.8, 22.6) |
| DAS28-ESR | 2.33 (1.67, 3.10) | 2.62 (1.89, 3.48) | 2.61 (1.62, 3.49) * | 3.03 (2.33, 3.77) | 3.03 (2.27, 3.83) | 2.85 (2.17, 3.62) |
| CDAI | 3.6 (1, 6.9) | 3.8 (1.3, 7.4) | 5 (1.9, 8.2) | 5.3 (2.03, 9.3) | 5.5 (2.2, 9.8) | 5.1 (2, 8.8) |
| SDAI | 3.9 (1.1, 7.2) | 4.3 (1.6, 8.6) | 5.3 (2.1, 9.4) * | 5.6 (2.3, 9.9) | 5.8 (2.4, 10.3) | 5.4 (2.1, 9.5) |
| TJC28 | 0 (0, 1) | 0 (0, 1) | 0 (0, 1) | 0 (0, 1) | 0 (0, 2) | 0 (0, 1) |
| SJC28 | 0 (0, 1) | 0 (0, 1) | 0 (0, 1) | 0 (0, 2) | 0 (0, 2) | 1 (0, 2) |
| PtGA, VAS, mm | 15 (4, 42) | 17 (6, 40) | 21 (6, 46) | 23 (8, 50) | 24 (8, 52) | 22 (8, 43) |
| CRP, mg/dl | 0.14 (0.05, 0.65) | 0.26 (0.07, 0.85) | 0.26 (0.08, 0.9) * | 0.13 (0.04, 0.51) | 0.12 (0.04, 0.5) | 0.11 (0.04, 0.45) |
| ESR, mm/h | 12.5 (6, 26) | 19 (9.0, 38) | 16 (6.4, 31) † | 24 (14, 40) | 22 (12, 39) | 20 (11, 33) † |
| RF, IU/ml | 22.5 (4, 76) | 51.5 (15.8, 165.5) | 93 (21.5, 362.5) † | 44 (16, 104) | 63 (21.5, 186.5) | 77 (22, 217) † |
| J-HAQ | 0 (0, 0.63) | 0.13 (0, 0.63) | 0.13 (0, 0.5) | 0.5 (0, 1.25) | 0.5 (0, 1.13) | 0.38 (0, 1) * |
| MTX use (%) | 69.8 | 65.9 | 73.1 | 72.1 | 72.5 | 76.4 |
| Corticosteroid use (%) | 34.6 | 43.6 | 37.5 | 38.0 | 39.9 | 38.9 |
| Biologics use (%) | 9.9 | 12.3 | 9.1 | 15.4 | 16.7 | 12.1 |
| MTX dose, mg/week | 7.85 (6, 10) | 8 (6, 10) | 8 (6, 10) | 8 (6, 10) | 8 (6, 10) | 8 (6, 10) |
| Corticosteroid dose, PSL equivalent, mg/day | 2.75 (2, 5) | 4 (2.225, 5) | 4 (2, 5) * | 3.1 (2, 5) | 3 (2, 5) | 3.9 (2.15, 5) |
↵* p value < 0.05.
↵† p < 0.01 by Kruskal-Wallis test or chi-squared test. BMI: body mass index; DAS28: 28-joint Disease Activity Score; ESR: erythrocyte sedimentation rate; CDAI: Clinical Disease Activity Index; SDAI: Simplified Disease Activity Index; TJC: tender joint count; SJC: swollen joint count; PtGA: patient’s global assessment; VAS: visual analog scale; CRP: C-reactive protein; RF: rheumatoid factor; J-HAQ: Japanese Health Assessment Questionnaire; MTX: methotrexate; PSL: prednisolone.