Table 4

Effect modification of SCD risk in users of AEMs

SCD cases
n=926
Controls
n=9832
OR* (95% CI)OR† (95% CI)OR‡ (95% CI)
Never used879 (94.9)9583 (97.5)1.0 (reference)1.0 (reference)1.0 (reference)
Past use24 (2.6)166 (1.7)1.5 (1.0 to 2.4)1.4 (0.9 to 2.3)1.4 (0.9 to 2.2)
Current use23 (2.5)83 (0.8)2.8 (1.7 to 4.6)2.5 (1.5 to 4.2)2.3 (1.4 to 3.9)
Duration of use (days)
 ≤302 (0.2)6 (0.06)2.6 (0.5 to 14.3)1.8 (0.3 to 11.0)0.9 (0.1 to 10.7)
 >3021 (2.3)77 (0.8)2.7 (1.6 to 4.6)2.6 (1.5 to 4.5)2.6 (1.1 to 6.0)
Effect modification
 Gender§
  Current use in females9 (1.0)34 (0.3)2.7 (1.2 to 6.1)2.7 (1.2 to 6.1)1.4 (0.3 to 6.0)
  Current use in males14 (1.5)49 (0.5)2.8 (1.5 to 5.3)2.5 (1.3 to 4.8)3.3 (1.1 to 8.5)
 Age (years)
  Current use in <657 (0.8)27 (0.3)4.4 (1.9 to 10.4)3.3 (1.3 to 8.4)2.7 (0.6 to 11.2)
  Current use in ≥6516 (1.7)56 (0.6)2.2 (1.2 to 4.1)2.2 (1.1 to 4.0)1.2 (0.3 to 4.3)
  • Data are expressed as number (%) unless otherwise indicated.

  • *ORs matched for age, gender, practice, and calendar time.

  • †ORs matched for age, gender, practice, and calendar time, adjusted for heart failure.

  • ‡ORs matched for age, gender, practice, and calendar time, adjusted for heart failure and epilepsy.

  • §There was no gender interaction among users of antiepileptic medications (p=0.88).

  • AEM, antiepileptic medication; SCD, sudden cardiac death.