Heller 1995

Methods	Randomised, parallel‐group, open‐label trial conducted in 2 centres in the UK 4 treatment arms: CBZ, PHB, PHT, VPS
Participants	Adults with newly diagnosed epilepsy (2 or more untreated partial or generalised tonic‐clonic seizures in the 12 months preceding the trial) Number randomised: CBZ = 61, PHB = 58, PHT = 63, VPS = 61 117 male participants (48%) 102 participants with partial epilepsy (42%) Mean age (range): 32 (13‐77) years
Interventions	Monotherapy with CBZ, PHB, PHT or VPS Median daily dose achieved: CBZ = 600 mg/d, PHB = 105 mg/d, PHT = 300 mg/d, VPS = 800 mg/d Range of follow‐up: 0‐166 months
Outcomes	Time to first seizure recurrence after start of therapy Time to 12‐month remission from all seizures Adverse effects and withdrawals due to adverse events
Notes	IPD provided for all outcomes of this review by the Medical Research Council
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation list generated using permuted blocks of size 8 or 16 with stratification for centre, seizure type and presence of neurological signs
Allocation concealment (selection bias)	Low risk	Allocation concealed via 4 batches of concealed, opaque envelopes
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unblinded, authors state masking of treatment would not be “practical” and would have “introduced bias due to a very large drop‐out rate.” Lack of blinding may have influenced the withdrawal rate.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Unblinded, authors state masking of treatment would not be “practical” and would have “introduced bias due to a very large drop‐out rate.” Lack of blinding may have influenced the withdrawal rate.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates reported, 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