Table 3. Factors associated with rheumatoid arthritis flare after switching from TCZ-IV to TCZ-SC.
| Variables | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| OR | CI | P value | OR | CI | P value | |
| Dose of TCZ-IV (mg/kg) at switching | 15.63 | 2.17–112.66 | 0.006** | 20.70 | 2.22–192.84 | 0.008** |
| Concomitant MTX non-use at switching | 6.66 | 1.34–32.52 | 0.020* | 8.53 | 1.21–60.40 | 0.032* |
| Concomitant steroid use at switching | 4.00 | 0.90–17.87 | 0.070 | |||
| Duration of using TCZ-IV < 1 yr | 2.70 | 0.63–11.51 | 0.179 | |||
| Previous use of 2 or more biologics | 1.88 | 0.44–7.99 | 0.395 | |||
| DAS28-ESR ≥ 2.6 at switching | 1.55 | 0.35–6.98 | 0.567 | |||
| Obesity (BMI ≥ 25) | 1.02 | 0.21–4.97 | 0.983 | |||
| Age at switching | 1.01 | 0.96–1.07 | 0.651 | |||
TCZ = tocilizumab, IV = intravenous, SC = subcutaneous, MTX = methotrexate, DAS28 = disease activity score in 28 joints, ESR = erythrocyte sedimentation rate, BMI = body mass index, OR = odds ratio, CI = confidence interval.
Statistically significant P values were marked with asterisks (*P < 0.05, **P < 0.01).