Development of a Pediatric Oncology Financial Toxicity Outcome Measure With Content and Face Validity: The...

To address a lack of validated outcome measures of financial toxicity in pediatric oncology settings, we developed a novel caregiver-reported instrument.

We first conducted qualitative concept elicitation interviews with family caregivers, then drafted de novo survey items guided by salient content domains. Items were reviewed by an expert panel who provided numeric ratings of item relevance to calculate content validity index (CVI), along with feedback on clarity and content. Items were removed or revised through a consensus process, organized into a preliminary measure, and forward- and back-translated to Spanish. We pretested items with caregivers in English and Spanish through iterative rounds of language-concordant cognitive interviews, revising between rounds to optimize comprehension, decision/response processes, and flow.

Concept elicitation with 21 caregivers (47% college-educated, 14% in Spanish) informed creation of 56 initial items across five content domains. CVI was <0.75 for 13 items; 12 were removed and one revised based on feedback. Of 43 items with CVI ≥0.75, eight were removed based on feedback and/or overlap with highly rated items. Thirty-six remaining items were revised and/or removed over six rounds of cognitive interviews with 22 different caregivers (42% college-educated, 23% in Spanish), then organized into a provisional 28-item instrument. In the final round of cognitive interviews, participants reported appropriate content, clarity, and organization in both languages.

We developed a novel caregiver-reported instrument to assess financial toxicity in pediatric oncology settings, with content and face validity. Future quantitative testing will evaluate its psychometric properties and other dimensions of validity to facilitate practical use.