Fig. 2

Forest plot of the six studies included in the quantitative synthesis for acute migraine treatment. The common outcome for these six studies was the proportion of patients who were pain free after 2 h in the active treatment and control groups (the higher the relative risk, the more effective the treatment). All references for studies in this figure are listed in the online supplementary references. RR: relative risk, TENS: transcutaneous electrical nerve stimulation, TMS: transcranial magnetic stimulation. The study by Hokenek et al. of 2020 [16] (supra-orbital TENS), was not included in the quantitative analysis