Background Pediatric patients with autonomic disorders often experience disabling symptoms such as fatigue, dizziness, abdominal pain, and syncope that limit daily functioning. The Functional Disability Inventory (FDI) is commonly used to assess disability in children and adolescents, with both self- and parent-report forms available. While prior studies show that children often report higher disability levels than their parents, little is known about the concordance of FDI scores in the context of autonomic disorders and symptom subtypes.

Methods This study assessed FDI scores from both pediatric patients and their caregivers at a autonomic disorder clinic. Additional symptom-based surveys were administered, including fatigue assessments, orthostatic intolerance profiles, and gastrointestinal symptom checklists, to explore correlations between symptom domains and disability perception. FDI sum scores from child and parent surveys were calculated and compared using paired t-tests. Pearson correlation coefficients were used to evaluate agreement between parent- and child-reported FDI scores. Subgroup analyses assessed whether specific symptoms were associated with greater parent-child scoring discrepancies.

Results A strong positive correlation was observed between child and parent FDI scores, suggesting that caregiver reports can serve as reliable proxies when child self-report is unavailable. Fatigue emerged as the strongest predictor of perceived disability across both respondent groups. On average, parents reported slightly higher levels of disability than their children, though the mean difference in FDI scores (–1.49) was not statistically significant (p = 0.1353). No substantial variation in FDI concordance was found across different autonomic diagnoses.

Conclusion Caregiver-reported FDI scores are closely aligned with child self-reports in pediatric patients with autonomic disorders, particularly when fatigue is a prominent symptom. These findings support the clinical use of parent reports as a valid substitute for self-reports in the functional assessment of pediatric autonomic patients. Future research should investigate longitudinal changes in FDI scores to track evolving perceptions of disability and treatment response.