Table 1. Demographic and clinical features of the patients.
| All patients (n = 165) | Standard-dose group (n = 49) | Tapering group (n = 116) | p value a | |
|---|---|---|---|---|
| Baseline (Starting TNFi treatment) | ||||
| Age, mean (S.D.) | 39.6 (12.6) | 42.5 (13.2) | 38.4 (12.2) | 0.057 |
| Male, n (%) | 142 (86.1) | 42 (85.7) | 100 (86.2) | 0.933 |
| BMI, mean (S.D.) | 23.2 (3.2) | 23.1 (3.2) | 23.2 (3.2) | 0.837 |
| Etanercept, n (%) | 58 (35.2) | 18 (36.7) | 40 (34.5) | 0.782 |
| Disease duration in years, mean (S.D.) | 9.3 (6.7) | 9.3 (7.9) | 9.2 (6.2) | 0.983 |
| HLA-B27 positive, n (%) b | 147 (91.9) | 43 (87.8) | 104 (93.7) | 0.205 |
| Current smoker, n (%) c | 46 (30.1) | 17 (36.2) | 29 (27.4) | 0.273 |
| Ever-smoker, n (%) c | 53 (34.6) | 21 (44.7) | 32 (30.2) | 0.082 |
| BASDAI, mean (S.D.) | 6.5 (1.7) | 7.1 (1.6) | 6.3 (1.6) | 0.003 |
| CRP > 0.5mg/dL, n, (%) | 119 (74.8) | 35 (74.5) | 84 (75.0) | 0.944 |
| Syndesmophyte at baseline, n (%) | 68 (41.2) | 27 (55.1) | 41 (35.3) | 0.018 |
| Number of syndesmophyte at baseline, mean (S.D.) | 2.8 (5.2) | 3.8 (5.4) | 2.4 (5.0) | 0.107 |
| Hip involvement at baseline, n (%) | 45 (27.8) | 13 (27.1) | 32 (28.1) | 0.898 |
| Baseline mSASSS, mean (S.D.) | 13.5 (16.6) | 17.3 (17.7) | 11.9 (16.0) | 0.059 |
| During the TNFi treatment | ||||
| Time-averaged CRP, mean (S.D.) d | 0.48 (0.44) | 0.46 (0.41) | 0.49 (0.45) | 0.710 |
| Time-averaged BASDAI, mean (S.D.) d | 2.1 (0.8) | 2.4 (0.8) | 1.9 (0.7) | <0.001 |
| Concomitant NSAID, n (%) | 123 (74.5) | 40 (81.6) | 83 (71.6) | 0.174 |
| High NSAID intake, n (%) | 22 (13.3) | 10 (20.4) | 12 (10.3) | 0.136 |
a p Values for comparison between the standard-dose group and the tapering group
b There were 5 missing values
c There were 12 missing values
d Mean value of those measured in the period between baseline and 45-month follow up
BASDAI, Bath Ankylosing Spondylitis Activity Index; CRP, C-reactive protein; HLA, human leukocyte antigen; NSAID, nonsteroidal antiinflammatory drug; S.D., standard deviation