Validation of the Greek OSD-6 quality of life questionnaire in children undergoing polysomnography

Objective

OSD-6 is a disease specific questionnaire for pediatric obstructive sleep apnea (OSA). The aims of this study were to validate OSD-6 in Greek language and correlate OSD-6 with polysomnography results.

Study design

Prospective study.

Setting

Tertiary referral center.

Subjects and methods

OSD-6 questionnaire was translated to Greek and back to English. A prospective study was conducted on children undergoing overnight polysomnography due to snoring and disrupted sleep. Test–retest evaluation was carried out. Internal consistency and test–retest reliability were evaluated. Validity was assessed by exploring correlations between OSD-6 scores and apnea–hypopnea index (AHI), and by comparing total scores of OSA and non-OSA groups. Responsiveness was assessed by comparing preoperative to postoperative total scores in OSA children who underwent adenotonsillectomy.

Results

Test–retest evaluation of 91 subjects showed good internal consistency (Cronbach’s alpha 0.860 for test and 0.873 for retest) and reliability (Pearson’s correlation coefficients between test and retest scores: 0.751–0.546; p < 0.01). Total and domains’ OSD-6 scores and AHI were significantly correlated (Spearman’s correlation coefficients: 0.277–0.630; p < 0.01), while children with OSA had higher total OSD-6 score than those without OSA (median (interquartile range): 16 (11) vs. 10 (7), respectively; p < 0.01), indicating good validity. Postoperative OSD-6 scores were significantly lower than preoperative (2.84 ± 3.21 vs. 15.42 ± 6.48, respectively; p < 0.001), suggesting good responsiveness.

Conclusion

The Greek version of the OSD-6 questionnaire proved to be a valid instrument with satisfactory internal consistency, reliability, validity and responsiveness. Furthermore, in our study OSD-6 was significantly correlated to polysomnography results.