Najafi 2013.

Study characteristics
Methods	Double‐blind, parallel‐group randomised controlled trial conducted at the Isfahan University of Medical Sciences between June 2011 and March 2012.
Participants	Female participants with either complex partial seizure, secondary generalised seizure, or primary generalised seizure and received full‑dose antiepileptic drugs. Seizure patterns had to be in the catamenial form, and seizure had to become exacerbated during the premenstrual period (between the 25th day of the previous cycle and the second day of the next cycle) or the whole period of the luteal phase of the cycle (2nd to 10th days of the cycle). Mean age 30.5 ± 8.5 years (overall). Progesterone group (n = 17): mean (SD) 29.2 (8.7); median (IQR) 27 (21.5 to 35). Placebo group (n = 19): mean (SD) 32.1 (8.3); median (IQR) 33 (26 to 36). Epilepsy duration (years, overall): mean 16.3 ± 9.3 years. Progesterone group (n = 17): mean (SD) 15.1 (9.7); median (IQR) 13 (9 to 18). Placebo group (n = 19): mean (SD) 17.5 (8.8); median (IQR) 15 (13 to 20). Seizures in the 3 months before the study (overall): mean 7.8 ± 7.2 years. Progesterone group (n = 17): mean (SD) 6.2 (3.4); median (IQR) 5 (4 to 8). Placebo group (n = 19): mean (SD) 7.6 (5.6); median (IQR) 8 (3 to 15).
Interventions	Two 40 mg progesterone tablets daily (twice a day) in the 2nd half of the cycle from 15th to 25th day. 2 placebo tablets daily in the same manner. 38 randomised (36 analysed): progesterone: 19 randomised/17 analysed; placebo: 19 randomised/19 analysed. All participants took concomitant antiepileptic drugs. Analysis after 3 months of follow‐up (monthly visits and number of seizures recorded).
Outcomes	Comparison of number of seizures during 3 months before and after the study.
Funding	No funding provided for the study.
Conflict of Interest	None declared.
Notes	No statistically significant difference in characteristics between groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Consecutive patients meeting the inclusion criteria were randomly divided into 2 groups using Random Allocation Software (Saghaei 2004).
Allocation concealment (selection bias)	Unclear risk	No information reported.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, placebo tablets were manufactured that were formally the same.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	2 participants in the progesterone group were excluded from the study due to adverse events. Only those who completed the study were analysed. Small participant numbers and no intention‐to‐treat approach may have affected the results.
Selective reporting (reporting bias)	Low risk	Outcome reported in the registry entry (seizure frequency at 3 months) was reported in the publication. Adverse events also reported.
Other bias	Low risk	Baseline characteristics across groups are balanced, no other sources of bias detected.

IQR: interquartile range
SD: standard deviation