STUDY OBJECTIVES: This study was conducted to validate the NoSAS score in 
clinical populations and to compare it with the Berlin, STOP, and STOP-Bang 
questionnaires, as well as the Epworth Sleepiness Scale (ESS), in screening for 
sleep-disordered breathing (SDB).
METHODS: A retrospective analysis was conducted of all patients aged 18 to 80 
years who had completed a full-night polysomnography (PSG) at the sleep center 
of the First Affiliated Hospital of Guangzhou Medical University from October 
2012 to November 2016. Patients who had incomplete or unanswered questionnaires 
were excluded. The data for the NoSAS score, ESS, STOP, STOP-Bang, and Berlin 
questionnaires were collected, after which the NoSAS score was compared against 
the other questionnaires for SDB screening.
RESULTS: A total of 2,208 participants were enrolled in this study. The NoSAS 
scores, which ranged from 0 to 17 and allocated a threshold of 8 points, 
identified individuals at risk of clinically significant SDB (defined as an 
apnea-hypopnea index [AHI] cutoff of ≥ 20 events/h), with an area under the 
curve (AUC) of 0.707. The NoSAS score performed significantly better than the 
STOP (AUC 0.655) and STOP-Bang (AUC 0.704) questionnaires and the ESS (AUC 
0.642), and it was at par with the Berlin (AUC 0.697) scores for SDB screening. 
A significant correlation was found between the AHI and NoSAS score (r = .386, P 
< .001).
CONCLUSIONS: The NoSAS score is a simple, efficient, and easy method for 
screening SDB in the clinical setting, especially in moderate to severe SDB. It 
demonstrates a moderately high level of sensitivity for SDB.