Methods | Randomised double-blind PCB and active drug controlled parallel multicentre (97 in Europe, Canada and Australia) trial. 3 treatment arms: 1 PCB, 1 PGB and 1 LTG. Patients randomised to 1 of 3 treatment arms (no further information available). Duration of baseline period: 6 weeks. 12-week treatment period with 5-week titration phase before treatment (1 week of titration for PGB and 5 weeks of titration for LTG) | |
Participants | Adults aged 16 to 82 years (mean 39.4 years), 48.5% male, all with treatment-resistant partial epilepsy confirmed by history and recent EEG. Patients were on 1 to 3 baseline AEDs. 546 patients screened, 434 patients randomised: 141 patients to PCB (mean baseline 28-day seizure frequency: 16.38), 152 patients to 150 mg to 300 mg PGB BD (mean baseline 28-day seizure frequency: 21.32), and 141 patients to 150 mg to 300 mg LTG BD (mean baseline 28-day seizure frequency: 21.80) | |
Interventions | Group 1: PCB Group 2: PGB 150 mg to 300 mg BD (1-week titration phase) Group 3: LTG 150 mg to 300 mg BD (5-week titration phase) |
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Outcomes | Primary outcome: change in seizure frequency compared to baseline (response ratio) Secondary outcomes: responder rate, seizure freedom, adverse events |
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Notes | One patient randomised to the PCB group failed to take > 1 dose of medication, and therefore was excluded from 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 | No details of method of randomisation |
Allocation concealment (selection bias) | Unclear risk | No details of concealment of allocation |
Blinding (performance bias and detection bias) All outcomes | Unclear risk | Same number of capsules administered per study day per group. No further details 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 |