Optimizing Numeric Pain Rating Scale administration for children: The effects of verbal anchor phrases.

: The 0-10 Verbal Numeric Rating Scale (VNRS) is commonly used to obtain self-reports of pain intensity in school-age children, but there is no standard verbal descriptor to define the most severe pain. : The aim of this study was to determine how verbal anchor phrases defining 10/10 on the VNRS are associated with children's reports of pain. . Children (= 131, age 6-11) rated hypothetical pain vignettes using six anchor phrases; scores were compared with criterion ratings. Though expected effects of age and vignette were found, no effects were found for variations in anchors. . Pediatric nurses (= 102) were asked how they would instruct a child to use the VNRS. Common themes of "the worst hurt you could ever imagine" and "the worst hurt you have ever had" to define 10/10 were identified. . Children's hospital patients (= 27, age 8-14) rated pain from a routine injection using four versions of the VNRS. Differences in ratings ranging from one to seven points on the scale occurred in the scores of 70% of children when the top anchor phrase was changed. Common themes in children's descriptions of 10/10 pain intensity were "hurts really bad" and "hurts very much." : This research supports attention to the details of instructions that health care professionals use when administering the VNRS. Use of the anchor phrase "the worst hurt you could ever imagine" is recommended for English-speaking, school-age children. Details of administration of the VNRS should be standardized and documented in research reports and in clinical use.