Chen 1996

Methods	Randomised, parallel‐group trial conducted in Taiwan 3 treatment arms: CBZ, PHB, VPS
Participants	Children with 2 or more previously untreated unprovoked epileptic seizures Number randomised: CBZ = 26, PHB = 25, VPS = 25; number analysed: CBZ = 25, PHB = 23, VPS = 25 (see notes) 38 boys (52%) 38 participants with partial epilepsy (52%) Mean age (range) for participants analysed: CBZ = 10.8 (7‐15 years), PHB = 9.9 (7‐15 years), VPS = 9.9 (7‐15 years)
Interventions	Monotherapy with CBZ, PHB or VPS Dose started or achieved not stated Trial duration: 12 months, range of follow‐up: not stated
Outcomes	Cognitive/psychometric outcomes: IQ (WISC‐R scale) and developmental delay (Bender‐Gestalt test) Auditory event‐related potentials (neurophysiological outcome) Incidence of allergic reactions Seizure control
Notes	2 children from the PHB group and 1 child from the CBZ group withdrew from the trial because of allergic reactions. Published results were presented for children who completed the trial only. Outcomes chosen for this review were not reported; IPD were not available
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were allocated with "simple randomisation of block size 3"
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	The cognitive assessor was "single blinded", implying that participants and personnel were unblinded, but no further information was provided
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The cognitive assessor was "single blinded"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Withdrawal rates were reported; results were presented only for those who completed the trial (3/73 (4%) excluded from analysis). An ITT approach was not taken but unclear whether the exclusion of this small proportion of participants would influence results
Selective reporting (reporting bias)	Low risk	All cognitive, efficacy, and tolerability outcomes specified in the methods sections were reported well in the results section. No protocol was available. Outcomes chosen for this review were not reported
Other bias	Low risk	None identified