Validation of the NoSAS score for screening sleep-disordered breathing: A sleep clinic- based study in Turkey

Turk J Med Sci. 2021 Feb 26;51(1):319-327. doi: 10.3906/sag-2002-54.


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.

Keywords: STOP-Bang; sleep-disordered breathing; NoSAS score; Berlin questionnaire.