Fig. 2

Assessment of change in Hb level: crude mean (± SD) change in Hb level from baseline to month 6 (A). Adjusted mean change (beta coefficient ± 95% CI) in Hb level from baseline to month 6, comparing IL-6Ri with TNFi and JAKi separately (B). Proportions of patients with low month 6 Hb level, proportions who changed from normal baseline to low month 6 Hb level, and proportions who changed from low baseline to normal month 6 Hb level (C). Odds of having a low month 6 Hb level, changing from normal baseline to low month 6 Hb level, or changing from low baseline to normal month 6 Hb level, comparing IL-6Ri with TNFi and JAKi separately (D). *p < 0.01; **p < 0.001. Low Hb was defined as < 12 g/dL (women) or < 13 g/dL (men). Adjusted model covariates were baseline Hb, age, duration of rheumatoid arthritis, morning stiffness duration, sex, current smoker status, prior use of one conventional synthetic disease-modifying anti-rheumatic drug, prior use of a non-TNFi biologic disease-modifying anti-rheumatic drug, white race, cyclic citrullinated peptide antibody positivity, combination therapy with methotrexate, and CDAI (baseline CDAI and 6-month CDAI). BL, baseline; CDAI, Clinical Disease Activity Index; CI, confidence interval; Hb, hemoglobin; IL-6Ri, interleukin-6 receptor inhibitor; JAKi, Janus kinase inhibitor; M, month; OR, odds ratio; SD, standard deviation; TNFi, tumor necrosis factor inhibitor