Comparison 2.

Aspirin 900 mg plus metoclopramide 10 mg versus placebo

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Headache relief at 2 hours	3	765	Risk Ratio (M-H, Fixed, 95% CI)	2.15 [1.78, 2.60]
2 Pain free at 2 hours	2	519	Risk Ratio (M-H, Fixed, 95% CI)	2.68 [1.59, 4.55]
3 24-hour sustained headache relief	1	257	Risk Ratio (M-H, Fixed, 95% CI)	2.18 [1.39, 3.41]
4 Relief of associated symptoms at 2 hours	2		Risk Ratio (M-H, Fixed, 95% CI)	Subtotals only
4.1 Nausea	2	417	Risk Ratio (M-H, Fixed, 95% CI)	7.53 [4.20, 13.50]
4.2 Vomiting	2	59	Risk Ratio (M-H, Fixed, 95% CI)	16.14 [2.30, 113.05]
5 Persistence of associated symptoms after 2 hours	2		Risk Ratio (M-H, Fixed, 95% CI)	Subtotals only
5.1 Nausea	2	735	Risk Ratio (M-H, Fixed, 95% CI)	0.69 [0.58, 0.82]
5.2 Vomiting	2	728	Risk Ratio (M-H, Fixed, 95% CI)	0.33 [0.18, 0.59]