Does greater exposure to own-health data make a difference on the visual analog scale?

The Visual Analog Scale (VAS) has become popular in eliciting valuations of health-related quality of life. The aim of the study was to explore the effect of greater exposure to own-health data on the VAS evaluation. A survey of 2,500 individuals included three measurements of the VAS, which differed in time and in the accumulated recall data to which the respondent had been exposed. Agreement among the three measurements was tested in several ways. The results generally showed that the VAS is a stable measure. The intraclass correlation coefficient (ICC) was 0.881. The paired t-tests indicated that the differences between the measurements were insignificant. More than half of the sample reported exactly the same VAS value in the three measurements. The use of the VAS measure, without any other preparation, seems to invoke the own-health data needed to report an accurate evaluation of health-related quality of life at any point in time.