Richens 1994

Methods	Open‐label, multicentre trial across 22 centres in the UK 2 treatment arms: CBZ and VPS
Participants	Adults with newly onset primary generalised epilepsy or partial epilepsy with/without generalisation or with a recurrence of seizures following withdrawal of AED treatment were eligible given that no anticonvulsants had been received in the previous 6 months Number randomised: CBZ = 151, VPS = 149 153 (51%) male participants (51%) 147 participants with partial epilepsy (49%) Mean age (range): 33 (16‐79) years
Interventions	Monotherapy with CBZ or VPS Mean daily dose achieved by month 24: CBZ = 516 mg/d, VPS = 924 mg/d Range of follow‐up: 0.5‐90 months
Outcomes	Remission analysis (time to 6‐, 12‐ and 24‐month remission) Retention analysis (time to treatment failure) Adverse event incidence Incidence of treatment failures due to poor seizure control and adverse events
Notes	IPD provided for all outcomes of this review by trial sponsor Sanofi. Participants with other generalised seizure types (e.g. myoclonic/absence) were included in the trial, but efficacy analyses were based solely on generalised tonic clonic seizures. Results in the published paper were given for 181 participants out of 300 analysed by ITT (participants randomised and with data for at least 1 follow‐up visit). IPD is provided for all 300 participants randomised and used for analyses in this review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised to treatment using a computerised minimisation programme with stratification for age, sex, seizure type and centre
Allocation concealment (selection bias)	Low risk	Treatment allocation was concealed via central telephone allocation from the Trial Office at Sanofi Winthrop LTD
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open‐label trial
Blinding of outcome assessment (detection bias) All outcomes	High risk	Open‐label trial
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates reported, ITT approach, all randomised participants analysed from IPD provided (see footnote 2)
Selective reporting (reporting bias)	Low risk	Protocol provided. All outcomes reported or calculated with IPD provided (see footnote 2)
Other bias	Low risk	None identified