Abstract
PURPOSE: Patient-reported outcomes are important clinical trial endpoints. Young children may not be able to reliably report on how they feel or function, so observer-reported outcomes (ObsROs) may be more appropriate for them. The purpose of this study was to develop and pilot field test electronic parent-reported observational instruments for children with cystic fibrosis (CF) 0-6 and 7-11years of age. METHODS: We performed concept elicitation interviews with parents of children with CF ≤11years of age to elicit the respiratory signs they could observe at baseline and during an acute respiratory illness. The resulting instruments were refined based on interviews with parents and clinicians. We conducted a pilot field test to evaluate test-retest reliability and the ability of items to distinguish well and sick periods. RESULTS: The instruments consist of 17 items assessing respiratory signs and observable CF-related impacts. Test-retest reliability was acceptable for both age groups but discrimination was low for ages 7-11, likely reflecting less direct observation of older children by their parents. CONCLUSIONS: An ObsRO for children with CF ages 0-6 appears promising, while self-report may be more appropriate for children >6years of age. Next steps for the 0-6year old instrument will be utilizing it as an exploratory endpoint in clinical trials to enable item reduction, scale development, and further reliability and validity testing. Ultimately, this ObsRO could be a promising endpoint for early intervention trials in young children with CF.