Development and validation of a postoperative nausea and vomiting intensity scale

BACKGROUND: Postoperative nausea and vomiting (PONV) is common and of concern to patients and clinicians. The effect of PONV can range from trivial and transient to major clinical importance, and it is unclear which of its characteristics lead to discomfort and distress. METHODS: We first enrolled 180 participants (patients, family members, nurses, doctors) to identify the characteristics of clinically important PONV, and from these data developed a measurement scale. We then evaluated the scale in a further 163 patients reporting PONV. Validity, reliability, and responsiveness of the PONV Intensity Scale were tested using psychometric techniques. RESULTS: Most participants agreed that three or more vomits, and greater nausea severity and duration, were key factors in defining clinically important PONV. These data were used to derive a PONV Intensity Scale and a score to define clinically important PONV. The scale identified 29 patients (18 ) as having clinically important PONV. Patients with clinically important PONV had a poorer quality of recovery (P