Comparison 1. Topiramate versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 50% reduction in seizure frequency ‐ Sensitivity analysis by study quality	3	283	Risk Ratio (M‐H, Fixed, 95% CI)	4.36 [2.24, 8.50]
2 50% reduction in seizure frequency ‐ ITT analysis	12	1650	Risk Ratio (IV, Random, 95% CI)	2.71 [2.05, 3.59]
3 50% reduction in seizure frequency ‐ Sensitivity analysis by patient characteristics (age)	11	1564	Risk Ratio (IV, Random, 95% CI)	2.85 [2.09, 3.88]
4 50% reduction in seizure frequency ‐ Sensitivity analysis by intervention (dosage)	9	1052	Risk Ratio (M‐H, Fixed, 95% CI)	3.32 [2.51, 4.38]
5 50% reduction in seizure frequency ‐ Best‐case analysis	12	1650	Risk Ratio (IV, Random, 95% CI)	3.54 [2.67, 4.69]
6 50% reduction in seizure frequency ‐ Worst‐case analysis	12	1650	Risk Ratio (IV, Random, 95% CI)	1.96 [1.54, 2.50]
7 Seizure freedom	8	1177	Risk Ratio (M‐H, Fixed, 95% CI)	3.67 [1.79, 7.54]
8 Treatment withdrawal	12	1650	Risk Ratio (M‐H, Fixed, 95% CI)	2.37 [1.66, 3.37]
9 Adverse effects	12		Risk Ratio (M‐H, Fixed, 99% CI)	Subtotals only
9.1 Ataxia	4	757	Risk Ratio (M‐H, Fixed, 99% CI)	2.29 [1.10, 4.77]
9.2 Difficulty with concentration/concentration impaired/concentration‐attention difficulties	6	702	Risk Ratio (M‐H, Fixed, 99% CI)	7.81 [2.08, 29.29]
9.3 Dizziness	8	1385	Risk Ratio (M‐H, Fixed, 99% CI)	1.52 [1.07, 2.16]
9.4 Fatigue	10	1427	Risk Ratio (M‐H, Fixed, 99% CI)	2.08 [1.37, 3.15]
9.5 Headache	9	1092	Risk Ratio (M‐H, Fixed, 99% CI)	0.96 [0.67, 1.39]
9.6 Nausea/vomiting	4	492	Risk Ratio (M‐H, Fixed, 99% CI)	1.50 [0.71, 3.15]
9.7 Paraesthesia	7	1071	Risk Ratio (M‐H, Fixed, 99% CI)	3.65 [1.58, 8.39]
9.8 Somnolence	9	1462	Risk Ratio (M‐H, Fixed, 99% CI)	2.44 [1.61, 3.68]
9.9 Speech difficulties/language problems	3	310	Risk Ratio (M‐H, Fixed, 99% CI)	3.37 [0.80, 14.13]
9.10 Thinking abnormally	4	640	Risk Ratio (M‐H, Fixed, 99% CI)	5.70 [2.26, 14.38]
9.11 Weight loss/decrease	9	1070	Risk Ratio (M‐H, Fixed, 99% CI)	3.99 [1.82, 8.72]