 Randomization and Blinding
Eligible participants were allocated to either placebo or gefapixant 45 mg BID in a 1:1 ratio. The randomization was stratified by sex and geographic region and was done by a centralized interactive response technology system. The randomization schedule was computer generated. This study used a double-blind design in which participants and all personnel involved with the conduct and the interpretation of the study were blinded to study treatment.