Table 4

Treatment withdrawal and seizure freedom rates (Kaplan–Meier estimates) for the VPA stratum for all patients and those with generalised seizures only, and for the CBZ stratum for all patients and those with focal seizures only (intent-to-treat population excluding unclassified/unknown seizure types)

VPA stratum
LEVVPA-EREstimated absolute difference* (95% CI)
Treatment withdrawal rate, % (95% CI)
 All patientsN=325N=323
  6 months16.9 (13.4 to 21.3)17.9 (14.2 to 22.3)−1.0 (−6.6 to 4.7)
  12 months22.0 (18.0 to 26.7)21.6 (17.7 to 26.4)0.3 (−5.8 to 6.5)
 Generalised seizures onlyN=226N=232
  6 months19.1 (14.5 to 24.8)18.1 (13.7 to 23.7)0.9 (−6.2 to 8.1)
  12 months24.1 (19.0 to 30.3)21.1 (16.4 to 27.0)3.0 (−4.7 to 10.7)
Seizure freedom rate, % (95% CI)
 All patientsN=325N=323
  6 months63.8 (58.3 to 68.8)69.2 (63.8 to 73.9)−5.4 (−12.7 to 1.9)
  12 months58.7 (53.1 to 63.9)64.5 (58.9 to 69.5)−5.7 (−13.4 to 1.9)
 Generalised seizures onlyN=226N=232
  6 months66.0 (59.0 to 72.1)73.0 (66.5 to 78.4)−7.5 (−16.4 to 1.3)
  12 months61.1 (53.9 to 67.5)68.3 (61.5 to 74.1)−7.2 (−16.5 to 2.1)
CBZ stratum
LEVCBZ-CREstimated absolute difference (95% CI)
Treatment withdrawal rate, % (95% CI)
 All patientsn=464n=480
  6 months18.7 (15.5 to 22.4)22.8 (19.4 to 26.7)−4.1 (−9.1 to 0.9)
  12 months25.2 (21.6 to 29.3)28.8 (25.1 to 33.0)−3.6 (−9.1 to 1.9)
 Focal seizures onlyn=418n=440
  6 months19.6 (16.1 to 23.8)23.4 (19.7 to 27.7)−3.8 (−9.3 to 1.7)
  12 months26.1 (22.2 to 30.6)29.6 (25.5 to 34.1)−3.4 (−9.4 to 2.5)
Seizure freedom rate, % (95% CI)
 All patientsn=464n=480
  6 months57.5 (52.8 to 61.9)62.0 (57.2 to 66.3)−4.2 (−10.7 to 2.2)
  12 months50.5 (45.8 to 55.1)56.7 (51.8 to 61.2)−6.1 (−12.8 to 0.5)
 Focal seizures onlyn=418n=440
  6 months55.5 (50.3 to 60.3)61.0 (56.0 to 65.7)−5.3 (−12.2 to 1.7)
  12 months48.1 (42.9 to 53.1)56.2 (51.0 to 61.0)−8.1 (−15.3 to −1.0)
  • * LEV/VPA-ER.

  • LEV/CBZ-CR.

  • CBZ, carbamazepine; CBZ-CR, controlled-release carbamazepine; LEV, levetiracetam; VPA, sodium valproate; VPA-ER, extended-release sodium valproate.