Table 3

Evaluation of the association of patient characteristics with QTc length

 SLE (n=50)RA (n=139)
Parameter estimatep ValueParameter estimatep Value
Age, years0.370.410.380.25
Female sex19.70.3512.20.03
Race/ethnicity
 White−39.50.17−2.80.73
 Hispanic−13.50.3214.20.67
 Black24.80.0914.20.67
Disease duration, years0.390.70−0.320.31
SLEDAI-2K−0.380.69
Lupus nephritis−11.80.31
APS−0.620.98
Moderate–severe disease activity*−3.80.755.30.36
DAS28-CRP3.20.24
CRP, mg/L−0.03†0.740.450.046
IL-6, pg/mL0.680.23
Antimalarials3.60.76−0.150.98
MMF−3.40.77
AZA34.50.07
Non-biologic DMARD−7.80.32
Biologic DMARD−3.90.49
Glucocorticoids−2.60.82−0.70.90
ds-DNA antibody12.80.39
SSA/anti-Ro1.560.90
SSB/anti-La−13.40.30
Sm antibody2.60.83
RNP antibody−1.490.90
RF>40 units−0.500.93
Anti-CCP>60 units0.800.89
Hypertension−0.920.9415.90.14
Diabetes−3.10.903.10.59
Current smoking−0.880.946.70.49
Aspirin−10.00.52−7.30.22
Statin−25.90.178.80.2
QT-modifying medications18.20.14−4.90.51
 Muscle relaxant, n (%)−8.10.848.20.50
 Antipsychotics, n (%)−28.00.3400
 Antidepressants, n (%)18.60.19−7.60.31
 Antimicrobials‡, n (%)−35.60.399.80.68
 Antiemetics, n (%)−1.50.94−8.00.68
ST-T abnormalities−4.00.739.30.21
  • Univariable linear regression parameter estimates and corresponding p values of the association of QTc duration with each listed variable.

  • *Moderate–severe disease activity is defined as SLEDAI-2K >6 or DAS28 CRP >3.2.

  • †n=40.

  • ‡Antimicrobials include macrolides, fluoroquinolones and HIV retrovirals.

  • Anti-CCP, anticitrullinated cyclic peptide; APS, antiphospholipid antibody syndrome; AZA, azathioprine; CRP, C reactive protein; DAS28, Disease Activity Score in 28 joints; DMARD, disease-modifying antirheumatic drug; IL-6, interleukin 6; MMF, mycophenolate mofetil; QTc, corrected QT-interval; RA, rheumatoid arthritis; RF, rheumatoid factor; SLE, systemic lupus erythematosus; SLEDAI-2K, Systemic Lupus Erythematosus Disease Activity Index 2000.