A Visual Analog Scale to assess anxiety in children during anesthesia induction (VAS-I): Results supporting its validity in a sample of day care surgery patients.

Abstract

The modified Yale Preoperative Anxiety Scale is widely used to assess children's anxiety during induction of anesthesia, but requires training and its administration is time-consuming. A Visual Analog Scale, in contrast, requires no training, is easy-to-use and quickly completed. The aim of this study was to evaluate a Visual Analog Scale as a tool to assess anxiety during induction of anesthesia and to determine cut-offs to distinguish between anxious and nonanxious children. Four hundred and one children (1.5-16 years) scheduled for daytime surgery were included. Children's anxiety during induction was rated by parents and anesthesiologists on a Visual Analog Scale and by a trained observer on the modified Yale Preoperative Anxiety Scale. Psychometric properties assessed were: (i) concurrent validity (correlations between parents' and anesthesiologists' Visual Analog Scale and modified Yale Preoperative Anxiety Scale scores); (ii) construct validity (differences between subgroups according to the children's age and the parents' anxiety as assessed by the State-Trait Anxiety Inventory); (iii) cross-informant agreement using Bland-Altman analysis; (iv) cut-offs to distinguish between anxious and nonanxious children (reference: modified Yale Preoperative Anxiety Scale ≥30). Correlations between parents' and anesthesiologists' Visual Analog Scale and modified Yale Preoperative Anxiety Scale scores were strong (0.68 and 0.73, respectively). Visual Analog Scale scores were higher for children ≤5 years compared to children aged ≥6. Visual Analog Scale scores of children of high-anxious parents were higher than those of low-anxious parents. The mean difference between parents' and anesthesiologists' Visual Analog Scale scores was 3.6, with 95% limits of agreement (-56.1 to 63.3). To classify anxious children, cut-offs for parents (≥37 mm) and anesthesiologists (≥30 mm) were established. The present data provide preliminary data for the validity of a Visual Analog Scale to assess children's anxiety during induction.