1. When is a meta-analysis helpful? EBM: 9/18/2012

2. Evidence-based medicine 25 year old woman presents with an acute migraine. She doesn’t respond to subcutaneous sumatriptan, intravenous metoclopramide, diphenhydramine, or ketorolac. Neurology consult: “Try dexamethasone. You should be using that routinely.”

3. Should I treat migraine with dexamethasone? Neurology. 2007 Nov 27;69(22):2038-44. Epub 2007 Oct 17.Randomized trial of IV dexamethasone for acute migraine in the emergency department. Friedman BW, Greenwald P, Bania TC, et.al. CJEM. 2006 Nov;8(6):393-400.Intravenous dexamethasone to prevent the recurrence of benign headache after discharge from the emergency department: a randomized, double-blind, placebo-controlled clinical trial. Baden EY, Hunter CJ.

4. Randomized trial of IV dexamethasone for acute migraine in the emergency department. Conclusion: A moderate dose of IV dexamethasone should not be administered routinely for the emergency department- based treatment of acute migraine, although it might be useful for patients with migraine lasting longer than 72 hours.

5. The numbers Dexamethasone: 39/ 106 with recurrence (0.37) Placebo: 43/99 with recurrence: 0.43 Relative risk: 37/.43=0.85

6. Forest plot

7. Intravenous dexamethasone to prevent the recurrence of benign headache after discharge from the emergency department: a randomized, double-blind, placebo-controlled clinical trial In this study, IV dexamethasone reduced headache recurrence at 48-72-hour follow-up. Given its excellent safety profile and likely benefit, IV dexamethasone should be considered for ED headache patients after standard evaluation and therapy.

8. The numbers Dexamethasone: 9/49=0.18 Placebo: 22/49=0.45 Relative risk: 0.18/0.45=0.4

9. Forest plot

10. Literature review You find 5 more RCTs of parenteral dexamethasone for acute migraine All of them are negative studies

11. Fig 2 Effectiveness of dexamethasone plus standard abortive therapy for recurrent migraine headache compared with placebo plus standard abortive therapy. Colman I, Friedman BW, Brown M, et.al.BMJ 2008;336:1359-1361 ©2008 by British Medical Journal Publishing Group

12. Bad Meta- analysis