Improving outcome measures for antiemetic efficacy trials in adult emergency department patients with nausea.

Nausea is a common problem for emergency department (ED) patients. The treatment objective is clinically significant symptom improvement during ED care. The traditional primary outcome measure is comparison of mean visual analog scale (VAS) rating change between groups. Interpretation of results is difficult, because this is an indirect and imprecise measure of symptom improvement. This research identified and tested a novel method using VAS change to identify improved patients. This directly aligns the primary outcome measure with the primary treatment objective. Between-group comparisons of symptom improvement rates ensure study results are presented in a clinically meaningful, easily understandable way.