Objective: To determine the construct, content, and convergent validity of 2 self-report pain scales for use in the untrained child in the emergency department (ED).
Methods: A prospective study was conducted of all children who presented to an urban ED between 5 and 16 years of age inclusive after written informed consent was obtained. Children were excluded if they were intoxicated, had altered sensorium, were clinically unstable, did not speak English, or had developmental delays. Children marked their current pain severity on a standardized Color Analog Scale (CAS) and a 7-point Faces Pain Scale (FPS). They were then asked whether their pain was mild, moderate, or severe. Children were then administered an analgesic at the discretion of the attending physician and asked to repeat these measurements. For assessing content validity, the scales were also administered to age- and gender-matched children in the ED for nonpainful conditions. Convergent validity was assessed by determining the Spearman correlation coefficient between the 2 pain scales.
Results: A total of 60 children were enrolled, 30 with pain and 30 without, with a mean age of 9.3 +/- 3.3 years. Boys accounted for 38 of the enrollees (63.3%). The median score before analgesic administration was 6.0 cm (interquartile range [IQR]: 4.0-8.0) on the CAS and 3.0 faces (IQR: 2.0-5.0) on the FPS; after analgesic administration, the median scores decreased to 3.1 cm (IQR: 1.1-4.3) and 2.0 faces (IQR: 1.0-3.0), respectively. As the reported pain intensity increased, so did the scores on the 2 pain scales. The 30 children with no pain had a median score on the CAS of 0.0 (IQR: 0.0-1.0) and on the FPS of 0.0 (IQR: 0.0-1.0), whereas the 13 children with severe pain had a median CAS of 7.0 (IQR: 6.0-8.0) and a median FPS of 5.0 (IQR: 4.0-6.0). The Spearman correlation coefficient between the CAS and the FPS was positive and strong (r = 0.894).
Conclusion: The CAS and the FPS exhibit construct, content, and convergent validity in the measurement of acute pain in children in the ED.