Pediatric pain measurement using a visual analogue scale: a comparison of two teaching methods

The goals of this study were to evaluate the validity of the visual analogue scale (VAS) for young children and to compare a newly developed method of teaching children to use a VAS with one used in our previous studies. It was hypothesized that the new method would increase the number of children who understand the VAS and correctly mark their responses on the VAS line. The association between child's age and ability to understand the VAS was also evaluated. One hundred-six children with a laceration requiring sutures and receiving a lidocaine injection for local anesthesia participated in the study. They ranged in age from 5 to 14 years. Two outcome measures were used to assess the baseline and lidocaine injection pain: a 5-point Likert scale and a VAS. A calibration study was used to determine whether the subjects were able to use the VAS to make proportional judgments about their perceptions. Teaching method had no effect on the number of subjects who could correctly mark their responses on the VAS line, nor did it significantly increase the number of subjects who could understand the concept of the VAS. Subjects who were able to understand the VAS were significantly older (mean = 9.8 years, SD = 2.8) than those who did not (mean = 8.2 years, SD = 2.5). Overall, only about one third of the subjects were able to correctly mark the VAS and understand the concept of the VAS. Other measures of pain that are better understood by young children may be more valid indicators of pain than the VAS.