SIMILARITIES AND DIFFERENCES IN ASSESSING NAUSEA ON A VERBAL CATEGORYSCALE AND A VISUAL ANALOG SCALE

The use of verbal category scales in assessing patient symptoms is evo lving, bur the extent to which reliability and precision are lost in u sing them as opposed to a visual analogue scale (VAS) remains uncertai n. The present study analyzed the concordance between a four-point ver bal category scale and a VAS irt assessing nausea intensity in patient s undergoing chemotherapy. The analysis of a total of 348 simultaneous ratings by 104 women over four cycles revealed good concordance betwe en the scales, The means of the VAS ratings (range 0-100 mm) correspon ding to the four verbal categories divided the scale in four almost eq ually large parts (no nausea = 0.7, mild = 24.8, moderate = 48.3, seve re 75.1). However, the VAS ranges were wine, On an individual level a one-step change in the verbal category was associated with an average change of 20 mm on the VAS. The choice of scale to use should be based on the need in the particular situation. When measuring intensity of nausea in patients, the VAS is a reasonable choice due to its possibly greater ability to detect changes over rime. On the group level, find ings on a four-point category scale and a VAS on the average seem simi lar.