Fig. 1
A flowchart presenting a selection process according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA 2020) [27]. n, number of studies
Fig. 1 | The Journal of Headache and Pain
A flowchart presenting a selection process according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA 2020) [27]. n, number of studies