Ogunrin 2005

Methods	Double‐blinded, parallel‐group, randomised study conducted in a single centre in Nigeria between October 2000 and October 2002 Three treatment arms: carbamazepine, phenytoin, phenobarbitone
Participants	Consecutive newly‐diagnosed people aged 14 or over presenting at the outpatient neurology clinic of the University Teaching Hopsital, Benin City, Nigeria with recurrent, untreated afebrile seizures Number randomised: PHT = 19, CBZ = 19 8 participants with partial seizures (22%), 23 men (62%). Mean age (range): 29.8 years (14 to 38 years) All participants followed up for 12 weeks
Interventions	Monotherapy with PHT or CBZ. Median daily dose (range): PHT = 200 mg (100 to 300 mg), CBZ = 600 mg (400 to 1200 mg)
Outcomes	Cognitive measures (reaction times, mental speed, memory, attention)
Notes	IPD provided for all randomised participants. Study duration was 12 weeks; all participants completed the study without withdrawing, so outcomes 'Time to withdrawal of allocated drug', 'Time to six‐month remission' and 'Time to 12‐month remission' could not be calculated. 'Time to first seizure' calculated from IPD provided Funding: Not stated Conflicts of interest: None stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Study randomised using simple randomisation. Each participant was asked to pick 1 from a table of numbers (1 ‐ 60), numbers corresponded to allocation of 1 of 3 drugs (information provided by author)
Allocation concealment (selection bias)	Low risk	Recruitment/randomisation of participants and allocation of treatments took place on different sites (information provided by author)
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants single‐blinded. Research assistant recruiting participants and counselling on medication adherence was not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Investigators performing cognitive assessments were single‐blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised participants completed the study. All randomised participants analysed from IPD provided1
Selective reporting (reporting bias)	Low risk	1 outcome for this review calculated from IPD provided1. Other outcomes for this review not available due to short study length. All cognitive outcomes from the study well reported
Other bias	Low risk	No other bias detected