Shakir 1981

Methods	Parallel‐design RCT conducted at 2 centres (Glasgow, Scotland and Wellington, New Zealand) 2 treatment arms: PHT and VPS
Participants	21 (64%) of participants previously untreated, 12 (36%) of participants continued to have seizures on previous drug therapies. Original treatments gradually withdrawn before PHT or VPS treatment introduced. Number randomised: PHT = 15, VPS = 18 12 male participants (36%) 19 participants with partial epilepsy (58%) Mean age (range): 23 (7‐55 years)
Interventions	Monotherapy with PHT or VPS Starting doses: PHT: < 12 years 150 mg/d, older participants: 300 mg/d, VPS: < 12 years 300‐400 mg/d, older participants: 800‐1200 mg/d. Doses achieved not stated. Mean follow‐up (range): 30 (9‐48 months)
Outcomes	Seizures during treatment Adverse events
Notes	Outcomes chosen for this review were not reported IPD not available but could be constructed from the publication for the outcome 'Time to treatment withdrawal.'
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants "randomly divided", using telephone randomisation (information provided by trial author)
Allocation concealment (selection bias)	Low risk	Centralised telephone randomisation used (information provided by trial author)
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No information provided
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided
Incomplete outcome data (attrition bias) All outcomes	Low risk	Results reported for all randomised participants, time on treatment reported for all randomised participants. No losses to follow‐up reported
Selective reporting (reporting bias)	Low risk	No protocol available, outcomes chosen for this review not reported, Seizure and adverse event outcomes well reported
Other bias	Low risk	None identified