Table 5

Multivariate analysis of clinical and laboratory variables at enrolment and occurrence of seizures regardless of attribution

Analysis IAnalysis IIAnalysis IIIAnalysis IV
PredictorHR (95% CI)p ValueHR (95% CI)p ValueHR (95% CI)p ValueHR (95% CI)p Value
Female gender0.61 (0.32 to 1.15)0.130.88 (0.25 to 3.04)0.841.10 (0.32 to 3.82)0.881.35 (0.39 to 4.62)0.64
Race/ethnicity0.030.240.570.43
 Caucasian
 Asian0.47 (0.18 to 1.23)Not estimableNot estimableNot estimable
 African1.97 (1.07 to 3.63)3.05 (0.99 to 9.45)2.12 (0.67 to 6.68)1.86 (0.67 to 5.14)
 Hispanic1.56 (0.80 to 3.04)1.82 (0.48 to 6.95)1.32 (0.33 to 5.34)1.11 (0.34 to 3.66)
 Other1.34 (0.41 to 4.42)1.13 (0.28 to 4.61)0.98 (0.23 to 4.09)0.68 (0.20 to 2.34)
Lack of postsecondary education1.96 (1.21 to 3.19)<0.014.55 (1.68 to 12.33)<0.014.07 (1.50 to 11.07)<0.013.05 (1.31 to 7.10)<0.01
Age at diagnosis*0.090.920.960.95
 Linear0.83 (0.63 to 1.09)0.91 (0.53 to 1.57)0.93 (0.53 to 1.63)0.93 (0.57 to 1.52)
 Quadratic1.21 (1.02 to 1.44)0.99 (0.67 to 1.46)1.00 (0.68 to 1.49)0.99 (0.67 to 1.45)
SDI score (w/o NP variables)0.030.07
 0
 13.93 (1.46 to 10.55)3.36 (1.26 to 9.02)
 2 or 31.57 (0.32 to 7.65)1.22 (0.25 to 5.95)
 ≥47.86 (0.89 to 69.06)5.22 (0.58 to 46.70)
Medications0.040.01
 Corticosteroids9.01 (1.14 to 71.44)5.87 (1.29 to 26.70)
 Antimalarials0.07 (0.01 to 0.66)0.10 (0.02 to 0.50)
 Immunosuppressants0.39 (0.11 to 1.43)0.46 (0.15 to 1.39)
 Interaction (antimalarials, immunosuppressants)13.85 (1.21 to 158.05)8.56 (1.33 to 55.16)
  • The total numbers of first seizures for analyses I–IV are 70, 20, 20 and 25, respectively. The number of patients included in analysis I was reduced to 70 due to missing data for postsecondary education status on 5 patients. In analyses II and III, the number was reduced to 20 because of the small number of SDI scores available due to either the inability to compute scores at the enrolment visit in patients with disease duration < 6 months or the occurrence of seizures prior to the enrolment visit.

  • * Age at diagnosis was standardised by taking (age at diagnosis-35)/14.

  • NP, neuropsychiatric; SDI, SLICC (Systemic Lupus International Collaborating Clinics)/ACR (American College of Rheumatology) Damage Index.