The Oswestry Disability Index is reflective of pain interference and mobility in children

Purpose: The 9-item Oswestry Disability Index version 2.1a (ODI-9) has never been formally validated in children. Our primary purpose was to evaluate the ODI-9 using the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Pain Interference (PI) and Mobility Computer Adapted Test (CAT) and Pain Catastrophizing Scale for Children (PCS-C) as anchors to determine concurrent validity in children. Methods: We retrospectively reviewed cross-sectional patient-reported outcomes data using a convenience sample of children referred to a tertiary pediatric orthopedic institution for any spine condition from April 2021 to April 2022. The ODI-9, PI, and Mobility were completed at clinic intake in 2,097 children (1453 girls, 644 boys) aged 14.2 ± 2.6 years (range 5–18 years) during the same visit. The ODI-9 was administered when children or caregivers responded “yes” to the presence of back pain. The PCS-C was administered only when pain intensity was rated as “very severe” or “the worst imaginable” on Item 1 of the ODI-9 (n = 51). Results: Average ODI-9 scores were 18.3% ± 14.8%, indicating minimal disability (ODI-9 ≤ 20%). Moderate, statistically and clinically significant associations were seen between the ODI-9 and PI (r = 0.68, p < 0.001), the ODI-9 and Mobility (r = − 0.68, p < 0.001), and the ODI-9 and PCS-C (r = 0.59, p < 0.001). Conclusion: Worse ODI-9 scores correlate with worse PROMIS PI scores, worse PROMIS Mobility scores, and worse PCS-C scores. The associations were moderate (PROMIS PI [r = 0.68], PROMIS Mobility [r = − 0.68], PCS-C [r = 0.59]).