Table 1

Baseline characteristics of CORRONA cohort newly initiating a DMARD with at least one follow-up visit (n = 2104 unique persons) by drug exposure

Drug exposure
MTX + LEFMTXLEFNo MTX or LEF
Number of treatment periods*1031342157502
Anti-TNF use (%)27.254.942.075.1
PsA diagnosis† (%)1.96.23.812.0
Mean (SD) age (years)58.8 (12.8)59.1 (13.3)59.4 (14.4)56.9 (14.9)
Mean (SD) duration of disease (years)12.9 (11.4)10.8 (9.8)11.0 (8.8)11.9
Female (%)80.674.078.370.9
White (%)83.584.785.982.4
Private insurance (%)76.676.672.478.0
Medicare insurance (%)42.937.545.737.1
Medicaid insurance (%)13.05.85.56.9
Current smoker (%)18.615.323.515.5
Mean (SD) BMI (kg/m2)28.7 (7.0)29.3 (7.1)27.9 (6.2)29.2 (7.5)
Diabetes (%)6.86.310.26.8
Liver disorder (%)6.83.77.09.2
Mean (SD) number of prior other non-biological DMARDs0.6 (0.8)0.8 (1.1)0.7 (1.0)0.8 (1.0)
Use of folic acid (%)76.676.628.423.6
Use of a cholesterol medication (%)18.216.320.515.1
Use of an NSAID (%)46.645.144.648.0
Drinking alcohol (%)
    None or occasional77.878.069.968.1
    1–3 drinks per week20.218.222.625.3
    1–2 per day2.03.97.56.6
    ⩾3 per day0.00.40.70.8
Daily prednisone dose
    None54.565.256.466.7
    <5 mg17.812.811.59.8
    5–10 mg21.815.219.215.0
    ⩾10 mg5.96.812.88.4
Health services utilisation during observation period after drug initiation
Mean (SD) number of follow-up visits2.9 (2.5)3.7 (2.6)3.4 (2.9)3.2 (2.5)
Mean (SD) number of follow-up visits with liver enzyme tests available2.3 (1.1)2.1 (1.0)2.2 (1.0)1.8 (1.0)
  • Data are shown as proportions unless otherwise stated.

  • *A treatment period indicates that a person was newly exposed to this drug or drug combination.

  • †Reflects the proportion of treatment periods contributed by patients with psoriatic arthritis; the remainder of the treatment periods were contributed by patients with rheumatoid arthritis.

  • BMI, body mass index; DMARD, disease-modifying antirheumatic drug; LEF, leflunomide; MTX, methotrexate; NSAID, non-steroidal anti-inflammatory drug; PsA; psoriatic arthritis; TNF, tumour necrosis factor.