Establishing the psychometric properties and preferences for the Northern Pain Scale

Objectives. A culturally relevant, evidence-based pain assessment scale in Inuktitut is needed. Psychometric properties and preferences for the Northern Pain Scale (NorthPS), a revised version of the Wong-Baker FACES scale, were examined. Study design. This repeated-measures, within-subjects study involved 2 face-to-face interviews held 2 weeks apart. Methods. Participants were recruited from 2 schools and a community centre in Pangnirtung, Nunavut, Canada. Three pain scales (NorthPS, FACES and a numerical rating scale) were used to rate the pain portrayed in an adapted version of the Charleston Pediatric Pain Pictures (NorthCPPP, a series of 17 cartoon vignettes). Results. The study involved 188 participants ranging in age from 5 to 83 years. Compared with the established FACES and numerical scales, the concurrent validity of the NorthPS was acceptable, with all 3 pain scales producing similar scores for the North CPPP vignettes. The youngest children were slightly more accurate during the second interview; otherwise, scoring accuracy was similar during both interviews. Accuracy was also similar across pain scales. Spearman correlations between NorthPS and other scales were lowest for the "No" pain vignettes, and for the youngest children. Internal consistency was acceptable for the NorthPS when compared with FACES and numerical scales. FACES was preferred by the majority of children and NorthPS was preferred by the majority of adults. Conclusions. NorthPS, a pain scale adapted to Inuit language and culture, was validated using the NorthCPPP with children and adults. The NorthPS is a well-understood, culturally and linguistically adapted option for the assessment of pain for Inuktitut-speaking children and adults.