Methods	Randomised double-blind PCB-controlled parallel multicentre (9 in Korea) trial. 2 treatment arms: 1 PCB, 1 PGB. Patients randomised to 1 of 2 treatment arms (no further information available). Duration of baseline period: 6 weeks. 12-week treatment period (no further details provided)
Participants	Patients 18 years and above (mean 34.2 years), 48.3% male, all with treatment-resistant partial epilepsy. Patients were on 1 to 3 baseline AEDs. 209 patients screened, 178 patients randomised: 59 patients to PCB (mean baseline 28-day seizure frequency: 13. 2) and 119 patients to 150 mg to 600 mg PGB (mean baseline 28-day seizure frequency 13.2)
Interventions	Group 1: PCB Group 2: 150 mg/day to 600 mg/day
Outcomes	Primary outcome: change in seizure frequency (response ratio) Secondary outcomes: responder rate, seizure freedom, anxiety/depression, sleep, quality of life, adverse events
Notes	All randomised patients included in ITT analysis. No information provided on methods of randomisation, concealment or blinding
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Patients randomised using 2:1 ratio. No further information given
Allocation concealment (selection bias)	Unclear risk	No information provided
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No information provided
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates reported. ITT analysis employed
Selective reporting (reporting bias)	Unclear risk	All outcomes stated in methods section of paper were reported in the results; however, there was no protocol available to check a priori outcomes
Other bias	High risk	Sponsored by same pharmaceutical company (Pfizer Ltd.) as with all the other included trials

AED: antiepileptic drug; BD: twice daily; EEG: electroencephalogram; GTCS: generalised tonic-clonic seizures; ITT: intention-to- treat analysis; LEV: levetiracetam; LTG: lamotrigine; PCB: placebo; PGB: pregabalin; TDS: three times a day