Reliability of the Color Analog Scale: Repeatability of Scores in Traumatic and Nontraumatic Injuries

Abstract

The objective was to assess in a pediatric emergency department (ED) the reliability of the color analog scale (CAS) for acute pain assessment, overall and between traumatic and nontraumatic pain etiology. This was a prospective study of children aged 5 to 16 years in the ED of a children's hospital who had a complaint of pain. The CAS was administered to the patient at admission and at 30 minutes. To evaluate repeatability, a second measurement was obtained 1 minute following each assessment. This assumed there would be no substantial change in pain intensity within 1 minute. The authors used the intraclass correlation coefficient (ICC) to evaluate the repeatability of 1-minute interval measurements. A total of 170 patients were enrolled. The origin of pain was traumatic in 81 cases (48%). Regardless of pain etiology, the CAS scores were highly repeatable (r = 0.97, 95% confidence interval [CI] = 0.95 to 0.98). The color analog scale is both a valid and a reliable self-reporting tool in the assessment of acute pain in children.