Visual analog scale rating change cut-offs for detection of improvement in nausea severity.

Abstract

Objective: To determine accuracy and best cut-point of measured and percentage visual analog scale (VAS) change for detection of symptom improvement. Method(s): A pooled analysis of three previously published studies was conducted. All patients had baseline and 30 min VAS ratings linked to described symptom change. A receiver operating characteristic curve analysis was performed. Result(s): Area under the curve for detecting symptom improvement was 0.86 (95% CI 0.83-0.90) and 0.87 (95% CI 0.84-0.90) for measured and percentage VAS change. Best cut-points were -8 mm and -20%. Conclusion(s): Accuracy of VAS change for detection of symptom improvement is good to excellent. Use of this outcome measure in future ED antiemetic trials is supported.Copyright © 2019 Australasian College for Emergency Medicine