Validation of the "Pain Block" concrete ordinal scale for children aged 4 to 7 years

Pain scales using faces are commonly used tools for assessing pain in children capable of communicating. However, some children require other types of pain scales because they have difficulties in understanding faces pain scales. The goal of this study was to develop and validate the "Pain Block" concrete ordinal scale for 4- to 7-year-old children. This was a multicenter prospective observational study in the emergency department. Psychometric properties (convergent validity, discriminative validity, responsivity, and reliability) were compared between the "Pain Block" pain scale and the Faces Pain Scale-Revised (FPS-R) to assess the validity of the "Pain Block" scale. A total of 163 children (mean age, 5.5 years) were included in this study. The correlation coefficient between the FPS-R and the Pain Block scale was 0.82 for all participants which increased with age. Agreement between the 2 pain scales was acceptable, with 95.0% of the values within the predetermined limit. The differences in mean scores between the painful group and nonpainful group were 3.3 (95% confidence interval, 2.6-4.1) and 3.8 (95% confidence interval, 3.1-4.6) for FPR-S and Pain Block, respectively. The pain scores for both pain scales were significantly decreased when analgesics or pain-relieving procedures were administered (difference in Pain Block, 2.4 [1.4-3.3]; and difference in FPS-R, 2.3 [1.3-3.3]). The Pain Block pain scale could be used to assess pain in 4- to 7-year-old children capable of understanding and counting up to the number 5, even if they do not understand the FPS-R pain scale.