Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies


OBJECTIVE: The objective of this selective evidence based medicine (EBM) review is to determine whether or not “Do injections of OnabotulinumtoxinA reduce migraine attack frequency in adults?”

STUDY DESIGN: A systematic review of three peer-reviewed studies published between 2015 and 2017.

DATA SOURCES: One randomized controlled trial; one randomized, double-blind, placebo-controlled clinical trial; and one observational, open-label, cohort study comparing frequency of migraine in adults when injected with OnabotulinumtoxinA (OBT-A). Based on their ability to answer the clinical question, articles were selected from PubMed and Cochrane Library.

OUTCOME(S) MEASURED: All articles were based on patient oriented outcomes and focused on mean change from baseline in number of migraine attacks per month. Self-reported questionnaires and diaries kept by patients were used to track number of attacks.

RESULTS: One study conducted (Ranoux D, Martiné G, Espagne-Dubreuilh G, et al. The journal of headache and pain. 2017;18(1): 75. doi:10.1186/s10194-017-0781-7) revealed a large treatment effect and high response rate with 41 of 63 having ≥ 50% reduction in headache days per month with OBT-A injection versus baseline (experimental event rate (EER)= 65.1%). In another study (Naderinabi B, Saberi A, Hashemi M, et al. Caspian J Intern Med. 2017; 8(3): 196-204. doi:10.22088/cjim.8.3.196) patients receiving OBT-A injections experienced a mean change from baseline of 12.4 and clinically significant improvement (P=0.0001) versus a control group of 5.2 during a three month period. In a third clinical trial (Hou M, Xie JF, Kong XP, et al. Toxins. 2015; 7(11): 4442-54. doi:10.3390/toxins7114442) patients were injected with OBT-A during a four month interval revealing a mean change in baseline of 7.2 to 3.5 headaches per month, and the study was clinically significant with a p-value of <0.01.

CONCLUSIONS: This review provides evidence from three separate studies that prophylactic injections with OBT-A greatly reduce the number of migraine attacks per month. Further research is warranted to provide more accurate time frames for efficacy and adverse effects (AE) compared to traditional prophylactic methods.