The Final 24-Item Early Onset Scoliosis Questionnaires (EOSQ-24): Validity, Reliability and Responsiveness

Abstract

Introduction The goal of early-onset scoliosis (EOS) treatment is to improve health-related quality of life (HRQoL) for patients and to reduce the burden on their parents or caregivers. The purpose of this study is to develop and finalize the 24-item Early-Onset Scoliosis Questionnaire (EOSQ-24), and examine the validity, reliability, and responsiveness of the EOSQ-24 in measuring patients’ HRQoL, the burden on their caregivers, and the burden on their caregiver’s finances. The study also established aged-matched normative values for the EOSQ-24. Methods The EOSQ-24 was administered to caregivers of male and female patients aged 0 to 18 years with EOS. Patients with EOS are diagnosed before 10 years of age. Criterion validity was investigated by measuring agreement between its scores and pulmonary function testing. Construct validity was established by comparing values across different etiology groups using the known-group method, and measuring internal consistency reliability. Content validity was confirmed by reviewing caregiver and health provider ratings for the relativity and clarity of the EOSQ-24 questions. Test-retest reliability was examined through intraclass correlation coefficients. Responsiveness of the EOSQ-24 before and after surgical interventions was also investigated. Age-matched, healthy patients, without spinal deformity, were enrolled to establish normative EOSQ-24 values. Results The pulmonary function subdomain score in the EOSQ-24 was positively correlated with pulmonary function testing values, establishing criterion validity. The EOSQ-24 scores for neuromuscular patients were significantly decreased compared with idiopathic or congenital/structural patients, demonstrating known-group validity. Internal consistency reliability of patients’ HRQoL was excellent (0.92), but Family Burden was questionable (0.64) indicating that Parental Burden and Financial Burden should be in separate domains. All 24 EOSQ items were rated as essential and clear, confirming content validity. All EOSQ-24 domains demonstrated good to excellent agreement (0.68 to 0.98) between test and retest scores. Neuromuscular patients improved their HRQoL postoperatively, whereas idiopathic patients worsened their HRQoL postoperatively, indicating the ability of the instrument to respond to different trajectories of HRQoL according to etiology in patients with EOS. Discussion The developed and finalized EOSQ-24 is a valid, reliable, and responsive instrument that is able to serve as a patient-reported outcome measure evaluating health status for patients with EOS and burden of their caregivers. This instrument will be able to serve as an outcome measure for future research including clinical trials evaluating the effectiveness of various treatments. In addition, the EOSQ-24 allows assessment of patients’ HRQoL, and the burden on their caregivers relative to age-matched healthy peers. Level of Evidence Level II—diagnostic study with consecutive patients enrolled in national registries.

Reliability and Construct Validity of the Adapted Norwegian Version of the Early-Onset Scoliosis 24-item Questionnaire

“… 23 , 24 The ICC agreement analysis showed good-to-excellent test-retest reliability between subjects, in agreement with a previous study. 13 The MDC total (15.2) and subdomain (21.6 to 33.0) scores were slightly higher than the results from corresponding patient-reported outcome measurements for adolescent idiopathic scoliosis and chronic low back pain. 29 , 30 This result indicates that the measurement error is considerable, particularly for the subdomain scores.…”

“…Corresponding to previous research, the Norwegian version demonstrated excellent internal consistency. 13 14 15 16 The interrelatedness among items was even higher when item 6, examining shortness of breath during physical activity, was deleted. The same item had also low distinction ability (α = 0.38).…”

“…These patients have previous shown significantly lower scores in subdomains who currently exhibited floor effects. 13 The potential challenge in follow-up examinations was further illuminated by the reliability analysis. Reliability is a useful parameter for discriminative purposes, whereas agreement is useful for follow-up examinations.…”

“…The EOSQ-24 total score decreased with increasing deformity and etiology complexity, as previously reported. 13 , 15 , 16 It discriminated between patients in an active surgical treatment period and those in a conservative treatment period. The use of growing rod instrumentation requires repetitive surgeries, with risk of complications.…”

“… 11 The final 24-item version questionnaire is reported to be reliable, valid, and responsive. 13 It has been translated and cross-culturally adapted into several languages, including Turkish, Spanish, and Chinese. 14 - 16 …”