On the Unidimensionality and Agreement of Four Self-Report Pain Intensity Scales: A Study with Arabic-Speaking Children and Adolescents

Purpose: The agreement of pain intensity reports is still a matter of controversy in pediatric pain studies. The aims of this study were to determine the unidimensionality of the electronic versions of four of the most widely used scales (i.e. eNRS-11, eVAS, eFPS-R and eCAS), and the level of agreement between their pain intensity scores, when used with Arabic-speaking children and adolescents.Methods: A convenience sample of 292 participants, including 137 children (8-12 years old) and 155 adolescents (13-18 years old) were asked to imagine themselves in a painful situation and rate the expected pain intensity using the four scales. A confirmatory factor analysis (CFA) was conducted to determine their unidimensionality. Subsequently, the level of agreement was calculated using the Bland-Altman method in the samples of children and adolescents independently. The maximum limit of agreement was set at +/- 2 with a confidence interval of 80% (CI).Results: The data showed the unidimensionality of the four scales and that, with a confidence interval of 80%, only the pain intensity reports of the eVAS and the eCAS in the sample of adolescents were concordant. The data showed no agreement among the pain intensity scores in the sample of children.Conclusions: The findings suggest that the Arabic versions of the four scales measure a single factor; pain intensity. However, only the scores of the eVAS and the eCAS in adolescents could be used interchangeably.