Table 4 Factors associated with longitudinal changes in TNFi trough serum levels over 1 year of follow-up using GEE multivariate models
Variable | TNFi trough serum levels | p value |
|---|---|---|
β coefficient (95% CI) | ||
DAS28-ESR | 0.26 (0.068–0.004) | 0.001 |
Reduced dose (yes/no) | 0.022 (0.168–0.012) | 0.271 |
Diagnosis (RA/PsA) | 0.005 (0.058–0.144) | 0.662 |
Monotherapy (yes/no) | 0.0004 (0.090–0.062) | 0.863 |
Follow-up | ||
 Baseline | 1 |  |
 4-month visit | 0.012 (0.044–0.0004) | 0.023 |
 8-month visit | 0.004 (0.032–0.002) | 0.280 |
 12-month visit | 0.002 (0.005–0.032) | 0.409 |
Steroids | 0.020 (0.325–0.090) | 0.538 |
Constant | 4.45 (2.99 to 6.25) | < 0.0001 |