title: The effectiveness of aspirin for migraine prophylaxis: a systematic review.
abstract: Many researchers have suggested that aspirin prevents migraines. However, the evidence is unclear. The aim of this study was to analyze the available evidence on the effect of aspirin as a migraine prophylactic.
  Systematic review, conducted at the Pontifícia Universidade Católica do Paraná, Brazil, and at the University of São Paulo, Brazil.
  We performed electronic searches in the databases of MEDLINE/PubMed, Embase, WEB OF SCIENCE, the World Health Organization, CENTRAL and OpenGrey, and we also searched manually for interventional studies published before April 2016 that compared the effects of aspirin with a control, in adults. Two authors independently extracted data on the publication, population recruited, intervention (aspirin dosage, follow-up and combined treatment) and main outcomes (frequency, severity and duration of migraine). We evaluated the quality of the studies using the Cochrane risk-of-bias tool.
  Our search retrieved 1,098 references, of which 8 met the selection criteria for this systematic review. The total population was 28,326 participants (18-64 years old); most (96%) were men. The dosage varied from 50 to 650 mg/day across the studies. The risk of bias was generally low or unclear. The only outcome for which most of the studies included (6/8) reported a significant reduction was frequency of migraine, which was reduced at an aspirin dosage of at least 325 mg/day.
  Aspirin can reduce the frequency of migraines. However, the optimal dosage is unclear.
authors.affiliation: MD, PhD. Professor, School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba (PR), Brazil.
authors.forename: Cristina Pellegrino
authors.initials: CP
authors.lastname: Baena
authors.affiliation: Medical Student, School of Medicine, Pontifícia Universidade Católica do Paraná (PUCPR), Curitiba (PR), Brazil.
authors.forename: Raíssa Campos
authors.initials: RC
authors.lastname: D'Amico
authors.affiliation: Medical Student, Faculdade Evangélica do Paraná (FEPAR), Curitiba (PR), Brazil.
authors.forename: Helena
authors.initials: H
authors.lastname: Slongo
authors.affiliation: MD. Professor, Hospital Universitário (HU), Universidade de São Paulo (USP), and Coordinator, Service of Interdisciplinary Neuromodulation (SIN), Laboratory of Neurosciences (LIM-27), Department and Institute of Psychiatry, Universidade de São Paulo (USP), São Paulo (SP), Brazil.
authors.forename: André Russowsky
authors.initials: AR
authors.lastname: Brunoni
authors.affiliation: MD. Epidemiologist, Hospital Universitário (HU), Universidade de São Paulo (USP), São Paulo (SP), Brazil.
authors.forename: Alessandra Carvalho
authors.initials: AC
authors.lastname: Goulart
authors.affiliation: MD, PhD. Professor, Hospital Universitário (HU), Universidade de São Paulo (USP), São Paulo (SP), Brazil.
authors.forename: Isabela
authors.initials: I
authors.lastname: Benseñor
mesh_terms: D001241:Aspirin / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000517:prevention & control*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin