Table 2

Summary of results of the included studies

Drug	No. of patients	Treatment		Control		RR treatment/control (95% CI)
Drug	No. of patients	No. of attacks/No. of courses	Ratio	No. of attacks/No. of courses	Ratio	RR treatment/control (95% CI)
Studies considering number of attacks per therapeutic course
Aminocaproic acid19	5	2/21	0.10	24/24	1.00	0.095 (0.025 to 0.356)
Danazol21	9	1/46	0.02	44/47	0.94	0.023 (0.003 to 0.162)

Drug	No. of patients	Treatment		Control		RR treatment/control (95% CI)
Drug	No. of patients	No. of attacks/No. of months	Ratio	No. of attacks/No. of months	Ratio	RR treatment/control (95% CI)
Studies considering number of attacks per months
Tranexamic acid20	12	32/94	0.34	63/57	1.11	0.308 (0.195 to 0.479)
Methyltestosterone22	4	4/46	0.09	19/12	1.61	0.054 (0.013 to 0.163)
C1 inhibitor23 ^*	22	131/63	2.07	267/63	4.24	0.491 (0.395 to 0.607)

↵* Number of attacks (expressed as attacks per month) was derived from the attack rate (expressed as attacks per 12 weeks) as reported in the study.