Issues in the measurement of nausea.

Measurement of nausea is essential for the evaluation of efficacy of antiemetic treatment. Frequency, duration and intensity of nausea should be assessed in all trials. Three different methods: a discrete scale (DS), a visual analogue scale (VAS) and a continuous chromatic analogue scale (ACCS) of measuring nausea and four different dimensions maximal intensity, (MI); entity, (E); duration, (D) and quantity, (Q) were evaluated in 849 cancer patients undergoing chemotherapy. A substantial agreement between the different scales was found and no advantage was shown for using an analogue (VAS) rather than a discrete (DS) scale. There was a trend towards increasing sensitivity in detecting differences as the dimension of nausea used encompassed wider aspects of this symptom (Q more sensitive than E more sensitive than MI).