title: Research Synthesis Methods special issue on network meta-analysis: introduction from the editors.
authors.affiliation: Department of Hygiene and Epidemiology, University of Ioannina Medical School, Ioannina, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Salanti
authors.affiliation: Warren Alpert Medical School, Brown University, Providence, RI, USA.
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Schmid