Patients’ interpretations of individual PROMIS-10 Global Health items: a cognitive interview study in high-impact chronic pain

PURPOSE: The purpose of this study was to explore the content validity of the Danish version of the PROMIS-10 Global Health questionnaire in patients with high-impact chronic pain by (1) identifying problematic items and reasons for misunderstandings between participants' interpretations and the intended meaning, and (2) exploring how participants understand and interpret the items. METHODS: Individual cognitive interviews were conducted with participants with high-impact chronic pain referred to two Danish Pain Centers using a structured step-by-step interview approach. The first objective was analyzed mainly using a deductive structured approach, while the second objective was analyzed mainly using an inductive thematic approach focusing on participants' perspectives. RESULTS: Participants (n = 19) generally understood the items as intended but showed 21% and 11% non-congruency for items 8r (fatigue) and 7r (pain intensity), as they responded based on a longer timeframe than "the past 7 days". Overall, participants interpreted the items through a physical, psychological and social perspective. Further, items 5 (social activities and relationships) and 6 (daily physical activities) were perceived to overlap thematically with item 9r (social activities and roles). Additionally, the provided examples in items 5 and 6 influenced responses, and some deemed item 7r irrelevant, as it did not reflect their pain experiences. CONCLUSION: The findings contribute to the validation of PROMIS-10 Global Health in patients with high-impact chronic pain by providing insights into how participants understand and interpret the items, highlighting areas for minor refinement. Further qualitative research on the validity of PROMIS-10 Global Health in this population is needed.