title: Measurement and monitoring of nausea severity in emergency department patients: a comparison of scales and exploration of treatment efficacy outcome measures.
abstract: OBJECTIVE
  The objective was to investigate the correlation of the visual analog scale (VAS) and numeric rating scale (NRS) for nausea severity measurement and to explore options for improved reporting of antiemetic efficacy trial results.
  
  
  METHODS
  This was a multicenter observational study of adult emergency department (ED) patients with nausea. Participants rated severity at enrollment and 30 minutes posttreatment using an adjectival scale, a VAS, and an NRS. Posttreatment, patients described symptom change and rated satisfaction.
  
  
  RESULTS
  Ratings were performed by 258 patients. Both the VAS (0 to 100 mm) and the NRS (0 to 10) discriminated between adjectival severity categories. Median ratings with interquartile ranges (IQRs) were "severe" VAS 90.5 (IQR = 79 to 97) and NRS 9 (IQR = 8 to 9), "moderate" VAS 59 (IQR = 48 to 71) and NRS 6 (IQR = 5 to 7), "mild" VAS 34 (IQR = 25 to 49) and NRS 4 (IQR = 3 to 5), and "none" VAS 5 (IQR = 0 to 9) and NRS 0 (IQR = 0 to 1). Correlation between the VAS and NRS was high (0.83, Spearman). For the VAS, median mm (IQR) reductions for posttreatment change were "a lot less" -42 (IQR = -26 to -58.5), "a little less" -20.5 (IQR = -11 to -33), "the same" -2 (IQR = -8 to 3.5), "a little more" 14 (IQR = -2 to 22), and "a lot more" 17 (IQR = 6 to 23) and for satisfaction were "very satisfied" -45 (IQR = -27 to 63), "satisfied" -27 (IQR = -13 to 46), "unsure" -15 (IQR = -3 to -24), "dissatisfied" 4.5 (IQR = -5.5 to 13.5), and "very dissatisfied" 8.5 (IQR = 0 to 23). A VAS cutoff of ≥-5 mm detected symptom improvement with sensitivity 91.6% (95% CI = 86.7% to 95.1%), specificity 72.1% (95% CI = 59.9% to 82.3%), and positive predictive value 90.2% (95% CI = 85.1% to 94.0%).
  
  
  CONCLUSIONS
  The VAS and NRS correlate highly. A VAS cutoff level of ≥-5 mm was a good predictor of symptom improvement, suggesting that its inclusion as an outcome measure would enhance reporting in antiemetic efficacy trials.
authors.affiliation: Department of Emergency Medicine, Monash Health, Melbourne, Victoria, Australia.|Department of Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Meek
authors.affiliation: Department of Emergency Medicine, Monash Health, Melbourne, Victoria, Australia.|Department of Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Diana
authors.initials: D
authors.lastname: Egerton-Warburton
authors.affiliation: Department of Emergency Medicine, Monash Health, Melbourne, Victoria, Australia.
authors.forename: Michaela J
authors.initials: MJ
authors.lastname: Mee
authors.affiliation: Department of Emergency Medicine, Monash Health, Melbourne, Victoria, Australia.|Department of Medicine, Monash University, Melbourne, Victoria, Australia.|Department of Emergency Medicine, Royal Melbourne Hospital, Melbourne, Victoria, Australia.|Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: George
authors.initials: G
authors.lastname: Braitberg
mesh_terms: D000328:Adult; D000932:Antiemetics / Q000627:therapeutic use*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000188:drug therapy*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010147:Pain Measurement / Q000379:methods*; D017060:Patient Satisfaction; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D064232:Visual Analog Scale
chemical_list: D000932:Antiemetics