Forsythe 1991

Methods	Single‐centre, randomised, parallel‐group trial. Three treatment arms: carbamazepine, phenytoin, sodium valproate Dates conducted and country: Not stated (assumed conducted in United Kingdom due to author affiliations)
Participants	Children with at least 3 newly‐diagnosed generalised or partial seizures within a period of 6 months Number randomised: PHT = 20, CBZ = 23 No information on epilepsy type, sex or range of follow‐up Age range: 5 to 14 years. Study duration: 12 months
Interventions	Monotherapy with PHT or CBZ Mean dose: PHT = 6.1 mg/day, CBZ = 17.9 mg/day
Outcomes	Cognitive assessments Summary of withdrawals from randomised drug
Notes	Outcomes chosen for this review were not reported IPD not available, but could be constructed from the publication for the outcome 'Time to withdrawal of allocated drug' Funding: A grant was obtained from the Yorkshire Regional Health Authority, support for measuring serum levels provided by Ciba‐Geigy PLC and Sanofi PLC. Conflicts of interest: None stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quota allocation by sex, age, seizure type and current treatment is an inadequate randomisation method
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	Personnel and participants (and parents) unblinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors single‐blinded for cognitive testing
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates reported, results reported and analysed for all participants randomised and all who completed various stages of follow‐up
Selective reporting (reporting bias)	Unclear risk	1 of 4 outcomes for this review reported. Cognitive outcomes described in Methods section well reported in Results section. Adverse effects reported, no seizure outcomes reported and outcomes chosen for this review not reported. No protocol available so unclear if seizure outcomes were planned a priori
Other bias	Low risk	No other bias detected