Lindberger 2000.

Methods	Randomised, double‐blind, dose titration study comparing gabapentin with vigabatrin (Denmark, Finland, Iceland, Norway and Sweden) 8‐week baseline period, 24‐week treatment period, evaluation period at 8 weeks compared with baseline. To allow flexibility, this was a dose adjustment regimen, with increases in doses of drug based on participant tolerance and seizure control, increased if required at 4‐week periods, with a maximum treatment period at each dose of 8 weeks.
Participants	Multicentre in 34 Nordic countries 102 participants randomised, then 35 (gabapentin group) and 44 (vigabatrin group) post exclusions for not for fulfilling criteria People with focal epilepsy who had tried no more than 2 AED monotherapy regimens
Interventions	Gabapentin: variable dose 1800 mg/day minimum, then 2400 mg then maximum 3600 mg/day, increased every 8 weeks as tolerated Vigabatrin: initial 1000 mg then 2000 mg then 4000 mg increased in the same manner as gabapentin
Outcomes	Primary outcome: improvement rate: proportion of participants with 50% seizure reduction without adverse effects Seizure reduction rate: proportion of participants with 50% seizure reduction irrespective of adverse effects Responder rate: proportion of seizure‐free participants without adverse effects Secondary outcomes: quality of life measures, adverse effects, perimetry
Notes	Results provided did not indicate the doses the participants had achieved of each drug
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not specified
Allocation concealment (selection bias)	Unclear risk	No details provided
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐dummy technique, participants received active drug and corresponding placebo
Incomplete outcome data (attrition bias) All outcomes	Low risk	Analysed on an ITT basis
Selective reporting (reporting bias)	Low risk	Seizure activity reported
Other bias	High risk	Trial sponsored by Parke Davis Study appeared free of other sources of bias