Table 2. Placebo controlled primary outcome (headache frequency per month).

Episodic Migraines
Time point	Weighted Mean Difference (95% CI)	Heterogeneity	Quality of Evidence (GRADE)
Acebutolol (HA frequency at baseline: 4.8 headaches/month (95% CI: -0.64 to 8.9))
Baseline Frequency	0.00 (-0.14 to 0.14)	—	Low
4 weeks	-0.20 (-0.38 to -0.02)	—
8 weeks	-0.50 (-1.6 to 0.63)	—
12 weeks	-0.6 (-1.7 to 0.53)	—
Alprenolol
8 weeks	-0.80 (-1.9 to 0.31)	—	Low
Atenolol
12 weeks	-1.7 (-3.0 to -0.32)	—	Low
Bisoprolol (HA frequency at baseline: 5.5 headaches/month (95% CI: 2.7 to 8.3))
Baseline			Low
5 mg	0.40 (-0.19 to 0.99)	—
10 mg	0.20 (-0.40 to 0.80)	—
4 weeks
5 mg	-0.40 (-1.1 to 0.29)	—
10 mg	-0.40 (-1.1 to 0.34)	—
8 weeks
5 mg	-0.50 (-1.2 to 0.25)	—
10 mg	-0.70 (-1.4 to -0.05)	—
12 weeks
5 mg	-0.90 (-1.53 to -0.27)	—
10 mg	-0.90 (-1.6 to -0.24)	—
Metoprolol (HA frequency at baseline: 3.9 headaches/month (3.1 to 4.7))
Baseline	-0.04 (-0.49 to 0.41)	Q = 3.68, df = 3, I2 = 18.5%	Low
4 weeks	-0.91 (-2.6 to 0.82)	—	—
8 weeks	-0.86(-1.4 to -0.34)	Q = 3.07, df = 2, I2 = 34.8%	Moderate
12 weeks	-0.90 (-2.2 to 0.41)	—	Low
Nadolol (HA frequency at baseline: 6.7 headaches/month (3.4 to 9.9)
Baseline	0.22 (-1.8 to 2.3)	—	Low
4 weeks	1.1 (-0.98 to 3.2)	—
8 weeks	-0.86 (-2.9 to 1.3)	—
12 weeks	-0.96 (-3.1 to 1.2)	—
Oxprenolol
8 weeks	-0.80 (-3.9 to 2.3)	—	Low
Propranolol (HA frequency at baseline: 4.8 headaches/month (4.3 to 5.3))—
Baseline	-0.04 (-0.28 to 0.20)	Q = 0.83, df = 10, I2 = 0.0%	High
4 weeks	-1.1 (-1.8 to -0.43)	Q = 0.0, df = 1, I2 = 0.0%	Moderate
8 weeks	-1.5 (-2.3 to -0.65)	Q = 11.37, df = 7, I2 = 38.4%	High
12 weeks	-1.2 (-1.8 to-0.60)	Q = 35.29, df = 8, I2 = 77.3%	High
16 weeks	-1.2 (-2.4 to -0.01)	—	Low
20 weeks	-0.9 (-1.8 to -0.02)	—	Low
24 weeks	-0.9 (-1.5 to -0.32)	—	Low
40 weeks	-0.3 (-0.9 to 0.34)	—	Low
64 weeks	-0.3 (-0.98 to 0.38)	—	Low
Timolol (HA frequency at baseline: 4.8 headaches/month (95% CI: -0.64 to 8.9))
Baseline	(-0.45 to 0.45)	Q = 0.0, df = 2, I2 = 0.0%	Moderate
8 weeks	-0.77 (-1.4 to -0.12)	Q = 1.03, df = 1, I2 = 3.2%
12 weeks	-1.53 (-2.5 to -0.78)	Q = 0.16, df = 1, I2 = 0.0%
Migraine-Chronic
Propranolol
8 weeks	-2.1 (-5.5 to 1.3)	—	Low
Chronic Tension-type HA
Pindolol+ Amitriptyline (HA frequency at baseline: 20.0 headaches/month (95% CI: 18.5 to 29.5))
Baseline	1.4 (-2.2 to 5.0)	—	Low
4 weeks	-7.8 (-13.9 to -1.5)	—
8 weeks	-11.2 (-16.7 to -5.5)	—
Propranolol (HA frequency at baseline: 20.0 headaches/month (95% CI: 18.5 to 29.5))
Baseline	(-8.1 to 8.1)	—	Low
8 weeks	-4.5 (-8.2 to -0.82)	—