Objective: To evaluate the clinical utility of the NoSAS score in the screening 
of patients with obstructive sleep apnea-hypopnea syndrome(OSAHS), and to 
compare the performance of the NoSAS score with other tools including Epworth 
Sleepiness Scale(ESS), STOP, STOP-Bang(SBQ) and Berlin questionnaires. Methods: 
A total of 444 consecutive patients(328 males and 116 females) with suspected 
OSAHS who underwent an overnight polysomnography(PSG) were recruited into this 
study. Five questionnaires including the NoSAS score, ESS, STOP, SBQ and Berlin 
were completed. Based on the severity of OSAHS which was determined by 
apnea-hypopnea index(AHI), the patients were classified into 4 groups: normal(<5 
events/h), mild(5-15 events/h), moderate(15-30 events/h) and, severe (≥30 
events/h) OSA.Sensitivity, specificity, positive predictive values, negative 
predictive values and the area under the receiver operating characteristics 
curve of 5 questionnaires were calculated. Results: With AHI≥5 events/h as the 
standard diagnosis of OSAHS, the NoSAS score and SBQ questionnaire showed a 
moderate performance, with the NoSAS score having the largest area under the ROC 
curve(0.753, P<0.001), followed by the SBQ questionnaire (0.727, P<0.001). The 
performance of the ESS, Berlin, and the STOP questionnaire was not high. Using 
mild moderate-severe(≥5 events/h), moderate-severe(≥15 events/h), and severe(≥30 
events/h)OSAHS as cutoffs, NoSAS had the highest specificity and positive 
predictive values(80.2% and 88%, 72% and 69.8%, 66.3% and 50.5%), and the 
sensitivity and negative predictive values were (51.5% and 36.9%, 56.5% and 
59.1%, 66.3% and 74.2%) .SBQ had the highest sensitivity and the negative 
predictive values(80.2% and 88%, 72% and 69.8%, 66.3% and 50.5%), and the 
specific and positive predictive values were (45.7% and 81.0%, 39.1% and 61.9%, 
34.8% and 44.4%). The NoSAS score ≥ 7 had higher sensitivity and negative 
predictive value(75.0% and 47.1%, 78.1% and 66.5%, 82.7% and 81.9%)than the 
NoSAS socre ≥ 8. With AHI≥5 events/h as the standard diagnosis of OSAHS, the 
NoSAS score and the SBQ questionnaire had a higher accuracy than the other 3 
questionnaires as screening questionnaires for diagnosing OSAHS, and the value 
of DOR were 4.298 and 3.758 respectively. Conclusions: The NoSAS score and the 
SBQ questionnaire have a moderate performance in diagnosing OSAHS. The NoSAS 
score is a new screening tool, and it is similar to the SBQ questionnaire, being 
also simple and effective. While the SBQ questionnaire is more widely used, it 
is necessary to further evaluate the diagnostic value of NoSAS score.