O2071: Validation of Early Onset Scoliosis 24-Item Questionnaire (EOSQ-24) in Patients with SMA Undergoing Spine Surgery

Background: Spinal muscular atrophy (SMA) is a congenital neuromuscular disorder characterized by SMN1 gene mutations/deletions causing motor neuron loss, progressive weakness, and skeletal deformity (Fig. 1). Preliminary data from our group revealed that genetic treatments aiming to increase production of functional SMN protein had little impact on onset/progression of early onset scoliosis (EOS). EOSQ-24 was validated to assess health-related quality of life (HRQoL) and burden of care of children with EOS. Original validation study included few SMA patients, thus assessing EOSQ-24 sensitivity to changes in HRQoL and burden of care in SMA children undergoing multi-modal (genetic + orthopedic) treatment is necessary.

Methods: Retrospective validation study using a convenience sample of EOS patients with SMA who underwent spine surgery at a single academic pediatric hospital 2008-2023. As part of an IRB approved multi-center EOS registry, EOSQ-24 (Domains: Children’s HRQoL, Parental Burden, Financial Burden, and Satisfaction) was administered to caregivers during routine hospital visits. Floor/ceiling effects defined as 15% of patients scoring the lowest/highest value in each domain. Known group validity testing achieved by comparing domain and sub-domain scores by SMA type. Criterion validity was assessed by anchoring EOSQ-24 scores to Revised Hammersmith Functional Motor Scale scores using Pearson’s correlation coefficients. Responsiveness was investigated by comparing perioperative ( < 1 yr post-op) to fully recovered (>/=1 yr postop) EOSQ-24 scores

Results: 62 EOSQ-24 forms were recorded for 23 SMA patients (mean age 9.28+/-3.03 yrs.; 49% female). 14 surveys were recorded for patients with hip instrumentation to correct dislocation. Average number of surveys completed: 2.7 (range:1-6). Surgeries included: magnetically controlled growing rod (MCGR) = 20 (87.0%); vertical expandable prosthetic titanium rib (VEPTR) /traditional growing rod (TGR) = 2 (8.7%); MCGR removal with definitive fusion = 4 (17.4%). No floor/ceiling effects were found. EOSQ-24 scores of SMA1 patients ( < 3 SMN2 copies) were lower in 6 of 8 HRQoL subdomains (General Health, Pulmonary, Transfer, Physical Function, Daily Living, Fatigue/Energy Level), parent burden and satisfaction compared to SMA2 patients (>2 SMN2 copies) (Fig. 2). EOSQ-24 HRQoL and Satisfaction scores positively correlated with Hammersmith scores [SMA1 (rs=0.63-0.74); SMA2 (rs=0.53-0.61)]. EOSQ-24 Parental (r=0.77) and Financial Burden (r=0.58) scores were positively correlated with Hammersmith scores only for SMA2 patients. EOSQ-24 scores >1yr post-op were consistently higher than perioperative scores (Fig. 2). EOSQ-24 subdomain scores were consistently higher in patients with hip instrumentation.

Conclusion: Results demonstrated EOSQ-24 is a valid and responsive outcome measure to assess HRQoL and burden of care in SMA patients undergoing spinal surgery. EOSQ-24 discriminated known HRQoL physical/functional differences between SMA1 and SMA2 patients, indicating excellent construct validity. Positive correlations with Hammersmith scores (gold standard SMA motor function measurement) established criterion validity. EOSQ-24 is responsive to surgical burden showing decreased HRQoL, burden of care, and satisfaction during acute recovery period.