Aspirin, 1000 mg, v placebo for acute migraine with moderate to severe pain*

Outcomes at 2 hoursAspirinPlaceboRBI (95% CI)NNT (CI)
*Abbreviations defined in glossary; RBI, RRI, NNT, NNH, and CI calculated from data in article.
†Response  =  change in pain intensity from moderate or severe at baseline to mild or none.
Response†52%34%53% (21 to 94)6 (4 to 12)
Pain free20%6%233% (83 to 513)8 (5 to 14)
Resolution of nausea52%43%21% (−2 to 49)Not significant
Resolution of photophobia30%14%114% (44 to 221)7 (5 to 13)
Resolution of phonophobia34%17%100% (40 to 188)6 (4 to 12)
RRI (95% CI)NNH
Any adverse event over 24 hours8.8%4.9%79% (−14 to 273)Not significant