1 AHS 2021. Ailani J, et al. American Headache Society. The American Headache Society Consensus Statement: Update on Integrating New Migraine Treatments Into Clinical Practice.
Headache. 2021 June 23. doi: 10.1111/head.14153.
Accessed online 7/20/21
AHS 2018 Effectiveness Ratings
• Established efficacy = More than 2 Class I trials
• Probably effective = 1 Class I or 2 Class I studies
• Possibly effective = 1 Class II study
2 NICE 2012 | 2021. National Institute for Health and Care Excellence. Clinical guideline (CG150). Headaches in over 12s: diagnosis and management. Published 19 September 2012. Last updated: 17 December 2021.
Accessed online 2/26/24
3 CHS 2013. Canadian Headache Society. Canadian Headache Society Guideline Acute Drug Therapy for Migraine Headache. 2013 Sept;40(5)Supplement3:1-80.
Free full-text PDF
CHS 2013 Recommendations and Evidence Gradings
• Strong rec: high-quality evidence = benefits clearly outweigh risks/burdens for most pts
• Strong rec: mod-quality evidence = benefits clearly outweigh risks/burdens for most pts, but recs could change w/ further research
• Strong rec: low-quality evidence = benefits clearly outweigh risks/burdens for majority of pts, but recs likely to change w/ research
• Weak rec: high-quality evidence = closer benefits w/ risks/burdens for most pts; use depends on pt case
• Weak rec: mod-quality evidence = closer benefits vs risks/burdens for most pts; more uncertain, depends on pt case
• Weak rec: low-quality evidence = closer benefits vs risks/burdens for most pts; considerable uncertainty re: use
4 AHS-ED 2016. Orr SL, et al. American Headache Society. Review Article. Management of Adults With Acute Migraine in the Emergency Department: The American Headache Society Evidence Assessment of Parenteral Pharmacotherapies.
Headache. 2016 Jun;56(6):911-40.
Free full-text PDF
AHS-ED 2016 Recommendation Level Classifications
• Level A = must offer; large value of benefit to risk; high confidence in evidence; compelling inferences
• Level B = should offer; mod value of benefit to risk; mod confidence in evidence; convincing inferences
• Level C = may offer; small value of benefit to risk; low confidence in EV; plausible inferences
• Level U = no recommendation; value of benefit to risk too close to call; very low confidence in evidence; inferences not plausible
5 CHS-ED 2013. Orr SL, et al. Canadian Headache Society. Canadian Headache Society Systematic Review and Recommendations on the Treatment of Migraine Pain in Emergency Settings.
Cephalalgia. 2015 Mar;35(3):271-84. Epub 2014 May 29.
Free full-text PDF
CHS-ED 2013 Recommendations and Evidence Gradings
• Strong rec: high-quality evidence = benefits clearly outweigh risks/burdens for most pts
• Strong rec: mod-quality evidence = benefits clearly outweigh risks/burdens for most pts, but recs could change w/ further research
• Strong rec: low-quality evidence = benefits clearly outweigh risks/burdens for majority of pts, but recs likely to change w/ research
• Weak rec: high-quality evidence; closer benefits w/ risks/burdens for most pts; use depends on pt case
• Weak rec: mod-quality evidence; closer benefits vs risks/burdens for most pts; more uncertain, depends on pt case
• Weak rec: low-quality evidence; closer benefits vs risks/burdens for most pts; considerable uncertainty re: use
6 FDA 2018. FDA Notification Regarding Isometheptene-Containing Drug Products. Published June 13, 2018.
Accessed 3/19/24 
