Can parents reliably report burn scar quality on behalf of their child? A clinimetric observational study of child-proxy agreement on the pediatric patient scale of the POSAS

BACKGROUND: The assessment of scar quality is an essential component of follow-up care and outcome evaluation in pediatric burn patients. The pediatric patient scale of the Patient and Observer Scar Assessment Scale (POSAS) is a recently developed patient-reported outcome measure (PROM) for this purpose. In pediatric care, proxy reports are commonly used when children are too young to self-report. However, the extent to which proxy reports reflect children's own perception of scar quality is unclear. This study evaluated child-proxy agreement on the pediatric patient scale of the POSAS. METHODOLOGY: In this clinimetric observational study, children aged 8-17 years with burn scars and their proxies (parent or other caregivers) were recruited at the Burn Center in Beverwijk, The Netherlands, and aftercare center OSCARE in Antwerp, Belgium. Both the child and a proxy independently completed the pediatric patient scale of the POSAS, with proxies instructed to report from the child's perspective (proxy-patient perspective). Child and proxy item scores were described using medians and interquartile ranges (IQR) and compared using the Wilcoxon signed-rank test. Effect sizes were calculated to quantify the magnitude of differences. Agreement was examined at two levels: (1) presence or absence of complaints and (2) severity ratings. Subgroup analyses were performed for age category and proxy type. RESULTS: A total of 81 child-proxy pairs were included between January and April 2025. Agreement on item level ranged from fair to substantial (kappa 0.309-0.692) and was moderate for most items. Overall agreement on the presence or absence of complaints was high (mean 78% concordance across items). Proxies reported worse scores than children for color, bumpiness, thickness, tightness, and lines, whereas children reported worse scores for hair growth (p < 0.05). Differences were generally small (≤1 response category). Agreement did not significantly differ across age groups or proxy type. CONCLUSIONS: In general, parents can report the presence or absence of their child's scar complaints and can provide an indication of the severity of the complaint. Proxy reports can meaningfully contribute to scar assessment in pediatric burn care and research when self-report is not possible. The decision to use proxy reports should be guided by the intended purpose of measurement.