Characteristics of the study population and increase of Hb levels after biologic therapies.

Continuous variables were compared by Mann-Whitney u-test and were expressed as median (min-max). Categorical variables were compared by Chi square test and were expressed as % (number) unless otherwise mentioned. Clinical response to biologic therapies was assessed by the reduction in CDAI, CRP or mHAQ from baseline to week 12. Increase of Hb levels (g/dl) was compared between the TCZ and the non-TCZ group and was expressed as median (Min-Max). TCZ, tocilizumab; RA, rheumatoid arthritis; BMI, body mass index; eGFR estimated glomerular filtration rate; Hb, hemoglobin; RBC, red blood cell count; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; LHD%, low hemoglobin density; CDAI, clinical disease activity index; CRP, C-reactive protein; mHAQ modified health assessment questionnaire-disability index; CCP, citrullinated protein/peptide; NSAIDs, non-steroidal anti-inflammatory drugs.连续变量采用Mann-Whitney U检验（Mann-Whitney u-test）进行组间比较，以中位数（最小值-最大值）的形式报告。分类变量采用卡方检验（Chi square test）进行组间比较，除另有说明外，以百分比（例数）的形式呈现。生物制剂治疗的临床疗效通过第12周时临床疾病活动指数（CDAI，clinical disease activity index）、C反应蛋白（CRP，C-reactive protein）或改良健康评估问卷残疾指数（mHAQ，modified health assessment questionnaire-disability index）相较于基线的降幅进行评估。血红蛋白（Hb，hemoglobin）水平（单位：g/dl）的升高幅度在托珠单抗（TCZ，tocilizumab）组与非托珠单抗组间进行比较，以中位数（最小值-最大值）形式呈现。托珠单抗（TCZ，tocilizumab）；类风湿关节炎（RA，rheumatoid arthritis）；体质量指数（BMI，body mass index）；估算肾小球滤过率（eGFR，estimated glomerular filtration rate）；血红蛋白（Hb，hemoglobin）；红细胞计数（RBC，red blood cell count）；平均红细胞体积（MCV，mean corpuscular volume）；平均红细胞血红蛋白量（MCH，mean corpuscular hemoglobin）；低血红蛋白密度（LHD%，low hemoglobin density）；临床疾病活动指数（CDAI，clinical disease activity index）；C反应蛋白（CRP，C-reactive protein）；改良健康评估问卷残疾指数（mHAQ，modified health assessment questionnaire-disability index）；瓜氨酸化蛋白/肽（CCP，citrullinated protein/peptide）；非甾体抗炎药（NSAIDs，non-steroidal anti-inflammatory drugs）。