Rosenfeld 1996.

Methods	Double‐blind, placebo‐controlled, parallel‐group study 2 treatment arms: 1 placebo, 1 topiramate Prospective pre‐randomisation baseline period: 8 weeks Treatment period: 19 weeks
Participants	A multicentre study (USA) 209 people were randomised (all with drug‐resistant focal epilepsy): 42 to placebo, 167 to 1000 mg topiramate Age range 18 to 65 years Mean age: Unknown 49% male Other AEDs: 1 Baseline seizure frequency (unknown). Patients had to have a minimum of 6 focal seizures during the 8‐week baseline phase
Interventions	1000 mg topiramate per day or placebo
Outcomes	Proportion with a 50% reduction in seizure frequency
Notes	Limited information regarding trial. All information was provided by a single poster abstract. Trial sponsored by Johnson & Johnson
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: random permuted blocks
Allocation concealment (selection bias)	Low risk	Comment: sealed, numbered packages allocated sequentially
Blinding (performance bias and detection bias) All outcomes	Low risk	Quote: "tablets were identical in appearance and packaging"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: only states "double‐blinded", and so blinding is likely though not confirmed
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: specific details of outcome assessment blinding not provided
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no concerns about missing data Quote: "intention‐to‐treat"
Selective reporting (reporting bias)	Low risk	Comment: appears all expected and prespecified outcomes are reported
Other bias	Low risk	Comment: the study appears to be free of other sources of bias