Usefulness of obstructive sleep apnea-18 as a predictor of moderate-to-severe obstructive sleep apnea in children who have normal/inconclusive McGill oximetry score

Context: Overnight oximetry is a screening test for pediatric obstructive sleep apnea (OSA). However, those who demonstrate normal/inconclusive test still require diagnostic polysomnography (PSG). Since PSG has a long waiting list, an adjunct simple test for the prioritization would be helpful. Aims: The aim of this study is to determine whether the OSA-18 quality of life (QoL) questionnaire could predict moderate-to-severe OSA in children with normal/inconclusive overnight oximetry. Settings and Design: The study involves a cross-sectional study at a university hospital. Subjects and Methods: Overnight PSG and QoL assessed by the Thai-Version OSA-18 were performed in snoring children with normal/inconclusive overnight oximetry. Statistical Analysis: Unpaired Student's t-test, Chi-square, and receiver operating characteristic curve analysis were used. Results: A total of 218 children (age 6.4 ± 2.5 years, 62% male) were studied. Sixty percent had moderate-to-severe OSA, while 40% had primary snoring/mild OSA. The mean total OSA-18 score was not different between the two groups. Subgroup analysis among those who never had medical treatment for OSA (n = 55) showed a higher total OSA-18 score in moderate-to-severe compared to primary snoring/mild OSA groups (80.5 ± 10.7 vs. 72.2 ± 14.4; P = 0.02). Total OSA-18 score >78 was the best cutoff value for predicting moderate-to-severe OSA (61.5% sensitivity, 80% specificity, 72.7% positive predictive value, and 69.7% negative predictive value). Combining this cutoff value with overweight/obesity did not improve its predictivity. Conclusions: We found the association between high total OSA-18 score and moderate-to-severe OSA in snoring children who had normal/inconclusive overnight oximetry and never had medical treatment for OSA. However, the best cutoff value of the score and other potential add-on parameters are still needed to be investigated.