2.3 Assessment of Clinical Data
The patients’ baseline characteristics were assessed by physicians and
recorded by clinical research assistants. Hypertension was diagnosed if
patients had a blood pressure of >140/90 mmHg on ≥2
occasions or were already on antihypertensive therapy. Diabetes was
diagnosed based on the classification of diabetes mellitus by an expert
committee. Dyslipidemia was diagnosed in patients with a history of
total cholesterol >240 mg/dL or those who received
lipid-lowering medication.
Parameters related to RA disease activity were also collected, including
swollen joint count based on the assessment of 28 joints (SJC28), tender
joint count based on assessment of 28 joints (TJC28), the presence of
rheumatoid factor (RF) and/or anti-citrullinated protein antibodies
(ACPA), C-reactive protein (CRP) level, erythrocyte sedimentation rate
(ESR), Health Assessment Questionnaire (HAQ) disability index score, and
the patient’s assessment of pain measured using a 100-mm visual analog
scale (VAS).
Disease activity of RA was evaluated with the disease activity score
28-joint count using erythrocyte sedimentation rate (DAS28-ESR),
Simplified Disease Activity Index (SDAI), Clinical Disease Activity
Index (CDAI), and physical disability by the HAQ index. SDAI, CDAI, and
DAS28-ESR were calculated using the following formulas: SDAI = SJC28 +
TJC28 + (VAS by patient) + (VAS by clinician) + CRP; CDAI = SJC28 +
TJC28 + (VAS by patient) + (VAS by clinician); DAS28-ESR = 0.56 × √(TJC)
+ 0.28 × √(SJC) + 0.7 × ln(ESR) + 0.014 × (VAS)14.
The DAS28-ESR disease activity of RA was defined as DAS28-ESR
<2.6 for remission, <3.2 for low disease activity,
≤5.1 for moderate disease activity, and >5.1 for high
disease activity. SDAI disease activity was defined as SDAI
<3.3 for remission, <11 for low disease activity,
≤26 for moderate disease activity, and >26 for high disease
activity. CDAI disease activity was defined as CDAI <2.8 for
remission, <10 for low disease activity, ≤22 for moderate
disease activity, and >22 for high disease activity. With
regard to treatment, the use of prednisolone, disease-modifying
anti-rheumatic drugs (DMARDs), methotrexate, and biologic agents were
collected.