Table 2 Factors associated with one or more thrombosis events in bivariate analyses
Explanatory variablesOR (95% CI)p Value
Female gender0.88 (0.59 to 1.32)0.498
Ethnicity
    Caucasian
    Hispanic
    African American0.865†
    Asian/Pacific Islander
    Other (mixed)
Age at SLE diagnosis (years)
    ⩽201.33 (0.80 to 2.23)0.274
    >20–⩽401.27 (0.79 to 2.05)0.325
    >401.24 (0.75 to 2.04)0.397
Duration of SLE (per 5 years)1.21 (1.14 to 1.29)0.013×10−7
Ever smoker1.27 (1.00 to 1.60)0.041
History of nephritis1.62 (1.28 to 2.06)0.045×10−3
History of immunomodulator therapy§1.52 (1.21 to 1.90)0.0002
History of prednisone treatment1.79 (1.21 to 2.73)0.0029
History of hydroxychloroquine treatment0.63 (0.48 to 0.83)0.0007
History of NSAID treatment1.00 (0.72 to 1.41)0.997
aPL¶2.79 (2.21 to 3.53)<10−9
    ACL positive1.95 (1.47 to 2.58)<10−9
    LAC positive3.35 (2.18 to 5.14)<10−9
  • ACL, anti-cardiolipin; aPL, antiphospholipid antibodies; LAC, lupus anticoagulant; NSAID, non-steroidal anti-inflammatory drugs; SLE, systemic lupus erythematosus.

  • *Significant results are shown in bold font.

  • †Omnibus test.

  • ‡Nephritis was defined as meeting American College of Rheumatology renal criterion, confirmed by review of medical records and/or renal biopsy consistent with lupus nephritis.

  • §Cyclophosphamide, azathioprine, methotrexate, ciclosporin, mycofenalate mofetil or chlorambucil. All medications were analysed as “ever” versus “never use”.

  • ¶aPL (ACL IgM or IgM or LAC (measured by Russell Viper Venom Time with confirmatory and mixing studies), positive at least once documented in records).