Crumrine 1989.

Methods	RCT, parallel
Participants	Total randomised: 73 Age range of patients = 2 to 18 years. Mean age for cinromide group = 7.38 (± 3.65), mean age for placebo group = 7.93 (± 4.87). All patients had Lennox‐Gastaut syndrome, although level of intellectual disability was not stated Patients could be on no more than 3 other AEDs Baseline period = 6 weeks. Treatment period = 18 weeks
Interventions	Cinromide versus placebo
Outcomes	The primary statistical analysis of seizure frequency compared the changes from the baseline period (6 weeks) to the treatment period (12 weeks for most patients) in the cinromide and placebo groups Global evaluations at weeks 12, 18 and 24 were also compared
Notes	Numbers used in data analysis = 56
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Although it states that participants were randomly assigned, information is not given about how randomisation was achieved
Allocation concealment (selection bias)	Unclear risk	Insufficient information
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Although it describes the trial as "double‐blind", there is insufficient information as to how blinding was achieved.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Although it describes the trial as "double‐blind", there is insufficient information as to how blinding was achieved.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Study attrition reported but reasons unclear
Selective reporting (reporting bias)	High risk	Very few P values reported
Other bias	High risk	Study was terminated early when it became clear to the funder that cinromide was not effective