BACKGROUND/AIM: The NoSAS score is a new tool for the identification of 
high-risk patients for sleep-disordered breathing (SDB). The aim of this study 
was to validate the NoSAS score in a sleep clinical population in Turkey and 
compare its performance with the Epworth Sleepiness Scale (ESS), STOP-Bang, and 
Berlin questionnaires for high-risk SDB.
MATERIALS AND METHODS: This was a retrospective study. Patients who had a 
full-night PSG examination between 01.03.2017 and 01.01.2018 at the sleep center 
of our hospital were included in the study. Demographic characteristics, 
anthropometrics measurements, ESS, STOP-Bang, and Berlin scores were collected 
from the existing data of the patients. The NoSAS score was subsequently 
calculated based on available data. Predictive parameters for each screening 
questionnaires were calculated to compare the discriminative power of those for 
high-risk SDB.
RESULTS: A total of 450 patients were included in the study. The sensitivity, 
specificity, PPV, and NPV of the NoSAS score were 81%, 51.2%, 88.2%, and 37.5% 
for an AHI (apnea–hypopnea index) ≥ 5 event/h and 84.5%, 38.2%, 66%, and 63.4% 
for an AHI ≥ 15 event/h, respectively. AUC percentages for the NoSAS score, 
STOP-Bang questionnaire, Berlin questionnaire, and ESS were 0.740, 0.737, 0.626, 
and 0.571 for an AHI ≥ 5 events/h and 0.715, 0.704, 0.574, and 0.621 for an AHI 
≥ 30 events/h. The NoSAS score had a false negative rate of 2.9% for severe SDB.
CONCLUSION: The NoSAS score had a good degree of differentiation for SDB and can 
be used as an easily applicable, subjective, and effective screening tool in a 
sleep clinical population in Turkey. Not only in moderate to severe SDB but also 
in mild SDB, the NoSAS score performed better than the other 3 screening tools.