Validation of the electronic Visual Analogue Scale of Anxiety.

Currently, the use of electronic scales is increasing rapidly, which is not surprising considering its accuracy, the ease of use and the increased compliance. The value of Visual Analogue Scales as a mean to objectify subjective variables has long been recognised. The current study aimed to validate the electronic Visual Analogue Scale of Anxiety (eVAAS). Seventy-one subjects, control subjects (n=46) and Panic Disorder patients (n=25), filled out the paper VAAS and the eVAAS in a randomised order. Panic was provoked using 35% CO(2) inhalation allowing us to include maximal scores in our analyses. The correlation between eVAAS and pVAAS was very strong and highly significant (r=0.98, p<0.001). pVAAS scores were slightly higher than eVAAS scores (p<0.001), but this difference is clinically unimportant. The VAAS established on a tablet PC is a useful and valid measure of anxiety and holds intrinsic benefits for anxiety assessment.