Cross-cultural adaptation and validation of the Greek OSA-18 questionnaire in children undergoing polysomnography

ObjectiveTranslations of validated questionnaires help to compare different countries/cultures populations and establish protocols for global health. OSA-18 is a validated disease-specific questionnaire for pediatric Obstructive Sleep Apnea (OSA). Our aim was to validate OSA-18 in Greek and correlate it with polysomnography results and OSA severity.Study designProspective instrument validation study.Subjects and methodsOSA-18 was translated in Greek and back into English. Children undergoing polysomnography due to snoring were recruited prospectively. OSA-18 was completed by parents during the initial clinic visit (test), in the evening prior to the sleep study (retest), and 3 months postoperatively for subjects who underwent adenotonsillectomy. Internal consistency and test–retest reliability were evaluated. Validity was assessed by exploring correlations between OSA-18 and AHI, by comparing OSA-18 of OSA and non-OSA groups, and by calculating questionnaire's sensitivity and specificity for detecting OSA. Total scores of non-OSA, mild, moderate and severe OSA subgroups were compared. In OSA children who underwent adenotonsillectomy, preoperative and postoperative total scores were compared to assess responsiveness.ResultsTest–retest questionnaires were fully completed for 141 children. OSA-18 in Greek had good internal consistency (Cronbach's alpha 0.951 for test and 0.947 for retest) and test–retest reliability (Pearson's correlation coefficients between test and retest scores: 0.850–0.946; P < 0.05). Total and subscale OSA-18 scores and AHI were significantly correlated (Spearman's correlation coefficients: 0.376–0.633; P < 0.01), while children with OSA had higher total OSA-18 score than those without OSA [median (interquartile range): 61 (35) vs. 38 (22), respectively; P < 0.001)]. Sensitivity was 53.4%, suggesting poor validity compared to polysomnography. All OSA severity subgroups had significant higher score than non-OSA. OSA-18 scores postoperatively were significantly lower compared to preoperatively (22.91 ± 5.49 vs. 67.13 ± 15.27, respectively; P < 0.001), indicating good responsiveness.ConclusionGreek OSA-18 is an instrument with satisfactory internal consistency, reliability, and responsiveness, but it is a poor predictor of OSA severity.