Mitchell 1987

Methods	Randomised, double‐blind, single‐centre, parallel paediatric trial conducted in Los Angeles, USA 2 treatment arms: CBZ and PHB
Participants	Children with newly diagnosed epilepsy Number randomised: PHB = 18, CBZ = 15 20 boys (61%) 100% of participants had partial epilepsy Mean age (range): PHB = 7.89 (2‐12 years), CBZ = 6.07 (2‐12 years)
Interventions	Monotherapy with PHB or CBZ Doses started and achieved not stated Trial duration: 12 months Range of follow‐up: not reported
Outcomes	Change in cognitive, intelligence (IQ), behavioural, and psychometric scores between baseline, 6 months, and 12 months Compliance, drug changes, and withdrawal rates Seizure control at 6 and 12 months (excellent/good/fair/poor)
Notes	33 participants were randomised to PHB (18) and CBZ (15) in this trial; 6 children were enrolled into a 6‐month pilot trial (PHB (4) CBZ (2)) prior to the randomised trial. The 6 children were included in 6‐month follow‐up psychometric data Outcomes for this review were not reported; IPD were not available
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	33 children were "randomised using a scheme that balanced drug distribution by age and sex"; no further details were provided on the randomisation scheme. 6 non‐randomised children were also used in some analyses
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	The trial blinded participants (and parents); clinicians were unblinded for clinical follow‐up
Blinding of outcome assessment (detection bias) All outcomes	High risk	The trial blinded participants (and parents); clinicians were unblinded for clinical follow‐up
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates were reported; results were reported for all children who completed each stage of follow‐up
Selective reporting (reporting bias)	Low risk	Cognitive/behavioural outcomes, seizure control outcomes, and adverse events were all well reported. No protocol was available; outcomes for this review were not reported
Other bias	High risk	There was evidence that the trial may have been underpowered to detect differences (e.g. 55% power to find a 5‐point difference in IQ score). The behavioural questionnaire was not fully validated. Non‐randomised children from a pilot trial were included in the results for psychometric outcomes and medical outcomes