Table 3. Baseline characteristics of patients at the time of TNF-α inhibitor initiation according to the reason for subsequent switching.
| Adverse event (n = 18) | Inefficacy (n = 45) | p-value | |
|---|---|---|---|
| Age, years | 38.0 (30.0–46.2) | 34.0 (27.5–45.5) | 0.394 |
| Males | 13 (72.2%) | 36 (80.0%) | 0.504 |
| Disease duration, years | 1.0 (0–5.2) | 1.0 (0–7.0) | 0.988 |
| Smoking | 6 (33.3%) | 14 (31.1%) | 1.000 |
| Alcohol consumption | 8 (44.4%) | 11 (24.4%) | 0.138 |
| Family history | 1 (5.9%) | 2 (5.4%) | 0.943 |
| History of joint surgery | 3 (16.7%) | 10 (22.2%) | 0.741 |
| Marital status | 10 (71.4%) | 15 (62.5%) | 0.577 |
| More than 12 years of education, years | 10 (55.6%) | 8 (17.8%) | 0.005 |
| Duration of 1st TNF α inhibitor use, months | 20.5 (10.7–34.2) | 21.0 (10.5–36.0) | 0.605 |
| BMI, kg/m2 | 25.1 (21.5–27.0) | 22.5 (19.7–24.6) | 0.066 |
| Uveitis | 6 (35.3%) | 6 (14.6%) | 0.085 |
| Peripheral arthritis | 6 (33.3%) | 13 (30.2%) | 0.812 |
| Complete ankylosis | 5 (27.8%) | 21 (50%) | 0.117 |
| BASDAI | 8.0 (5.4–9.0) | 6.7 (5.5–7.8) | 0.205 |
| WBC, 103/mm3 | 8.1 (6.5–8.6) | 8.3 (7.1–9.3) | 0.223 |
| Hemoglobin, g/dL | 13.0 (12.0–14.6) | 12.6 (11.4–14.5) | 0.429 |
| Platelets, 103/mm3 | 306.0 (251–358.5) | 315.0 (269.0–391.0) | 0.304 |
| ESR, mm/h | 48.5 (31.5–66.7) | 52.5 (25.5–88.7) | 0.926 |
| CRP, mg/dL | 1.3 (0.5–2.6) | 2.8 (1.2–6.3) | 0.065 |
| AST, U/L | 23.0 (16.0–34.2) | 20.0 (16.5–23.5) | 0.214 |
| ALT, U/L | 14.5 (11.5–36.0) | 16.0 (11.5–23.5) | 0.964 |
| Total bilirubin, mg/dL | 0.56 (0.43–0.70) | 0.50 (0.40–0.67) | 0.625 |
| Creatinine, mg/dL | 0.75 (0.67–0.82) | 0.70 (0.60–0.85) | 0.681 |
| HLA B27 positivity | 15 (83.3%) | 37 (92.5%) | 0.300 |
| INH prophylaxis | 10 (55.6%) | 18 (40%) | 0.265 |
| NSAIDs | 8 (44.4%) | 29 (64.4%) | 0.149 |
| Prednisolone | 1 (5.6%) | 10 (22.2%) | 0.147 |
| Methotrexate | 5 (27.8%) | 19 (42.2%) | 0.290 |
| Sulfasalazine | 6 (33.3%) | 12 (26.7%) | 0.597 |
| Any DMARDs | 7 (38.9%) | 27 (60%) | 0.133 |
| Median dose of methotrexate, mg/week | 7.5 (7.5–8.7) | 12.5 (7.5–15.0) | 0.044 |
| Median dose of sulfasalazine, g/day | 1.0 (1.0–2.0) | 1.0 (1.0–2.0) | 0.898 |
TNF, tumor necrosis factor; BMI, body mass index; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; AST, aspartate aminotransferase; ALT, alanine aminotransferase; INH, isoniazid; NSAIDs, non-steroidal anti-inflammatory drugs; DMARDs, disease-modifying anti-rheumatic drugs.
Continuous variables are shown as medians and interquartile range.