Agreement Between Verbal and Electronic Versions of the Numerical Rating Scale (NRS-11) when Used to Assess Pain Intensity in Adolescents

Objectives: Electronic pain measures are becoming common tools in the assessment of pediatric pain intensity. The aims of this study were (1) to examine the agreement between the verbal and the electronic versions of the 11-point Numerical Rating Scale (NRS-11) (vNRS-11 and eNRS-11, respectively) when used to assess pain intensity in adolescents; and (2) to report participants' preferences for each of the 2 alternatives. Materials and Methods: A total of 191 school children enrolled in grades 7 to 11 (mean age, 14.61; range, 12 to 18) participated. They were asked to report the highest intensity of the most frequent pain that they had experienced during the last 3 months using both the vNRS-11 and the eNRS-11. Agreement analyses were carried out using: (1) the Bland-Altman method, with confidence intervals (CI) of both 95% and 80%, and a maximum limit of agreement of +/- 1; and (2) weighted intrarater kappa-coefficients between the ratings for each participant on the vNRS-11 and eNRS-11. Results: The limits of agreement at 95% fell outside the limit established a priori (scores ranged from - 1.42 to 1.69), except for participants in grade 11 (- 0.80, 0.88). Meanwhile, the limits of agreement at 80% CI fell inside the maximum limit established a priori (scores ranged from - 0.88 to 0.94), except for participants in grade 8 (Supplemental Digital Content 2, http://links.lww.com/CJP/A97) (- 0.88, 1.16). The kappa-coefficients ranged from 0.786 to 0.912, indicating "almost perfect" agreement. A total of 83% of participants preferred the eNRS-11. Discussion: Pain intensity ratings on the vNRS-11 and eNRS-11 seem to be comparable, at least for the 80% CI.