Ben‐Menachem 1996.

Methods	Double‐blind, placebo‐controlled, parallel‐group study 2 treatment arms: 1 placebo, 1 topiramate Pre‐randomisation baseline period: 8 weeks Treatment period: 13 weeks
Participants	A multicentre study (Sweden, Norway, Denmark, Germany) 56 people randomised (all with drug‐resistant focal epilepsy): 28 to placebo and 28 to 800 mg topiramate Age range: 18 to 65 years Mean age: 37.2 years 84% males Other AEDs: 2 or fewer Median baseline monthly seizure frequency: 11.4 for placebo group, 14.2 for topiramate group
Interventions	800 mg topiramate per day or placebo
Outcomes	Percentage reduction in generalised seizure rate Percentage responders (50% and 75%) Adverse effects
Notes	Trial sponsored by Johnson & Johnson
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computer‐generated randomization schedule" 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	Comment: identical tablets and packaging
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: it is likely that blinding was maintained due to the methods used
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: all participants were included in the analysis Quote: "intention‐to‐treat analysis"
Selective reporting (reporting bias)	Low risk	Comment: protocol unavailable, but appears all expected and prespecified outcomes are reported
Other bias	Low risk	Comment: the study appears to be free of other sources of bias