Reliability and Validity of the Adapted Dutch Version of the Early-Onset Scoliosis-24-Item Questionnaire (EOSQ-24)

Abstract

STUDY DESIGN: Translation and validation of the Early Onset Scoliosis-24 Questionnaire (EOSQ-24). OBJECTIVE: To cross-culturally adapt the English version of the EOSQ-24 to the Dutch language and to assess the questionnaire's reliability and validity. SUMMARY OF BACKGROUND DATA: Early-onset scoliosis (EOS) has a profound impact on health-related quality of life. The EOSQ-24 is health-related quality of life questionnaire filled in by parents of children with EOS. The EOSQ-24 was already translated into multiple languages and its application was confirmed in clinical studies. However, the EOSQ-24 is not yet translated and validated for the Dutch population. METHODS: The adaption of the EOSQ-24 for the Dutch population was done in three steps: 1) translation to the Dutch language, 2) cross-cultural adaptation, and 3) cross-cultural validation. To ensure that the Adapted Dutch EOSQ-24 is applicable for clinical use, the measurement properties were tested in four steps: 1) floor and ceiling effects, 2) validation, 3) reliability, and 4) discriminative ability. One hundred three parents completed the Adapted Dutch EOSQ-24, the Child Health Questionnaire (CHQ-28 PF), and the Scoliosis Research Society Questionnaire (SRS-22r). A second EOSQ-24 was completed for test-retest reproducibility. RESULTS: The EOSQ-24 was successfully translated, adapted, and validated for the Dutch language. Almost all response items showed a normal distribution. The EOSQ-24 showed excellent reliability (Cronbach α of 0.950). The EOSQ-24 was successfully validated against the CHQ-28-PF and the SRS-22r. Test-retest was excellent (ICC ≥ 0.8). Finally, The EOSQ-24 was found capable to discriminate patients with different curve severities (P = 0.003), diagnosis (P = 0.006), and ambulatory status (P < 0.001). CONCLUSION: The current Dutch EOSQ-24 proved to be a valid and reliable quality of life assessment tool for patients with EOS. Currently, long follow-up studies using the EOSQ-24, including the Dutch EOSQ-24, are lacking and are needed to fully validate the EOSQ-24 for use in a clinical setting. LEVEL OF EVIDENCE: 2.