Predictive value of Berlin Questionnaire and Epworth Sleepiness Scale for obstructive sleep apnea in a sleep clinic population


  • Authorship and contributorship

    SSU designed the study, conducted the study, collected and analyzed data, and prepared the manuscript. EG and TK helped in analysis of data and prepared the manuscript. OA, BH and SU helped in the conduction of the study and collection of data. MU helped in the conduction of the study, and preparation of the manuscript. All authors read and approved the final manuscript.

  • Ethics

    The study protocol complies with the Helsinki Declaration of 2000, and the research protocol was approved by the institutional review board of our university. All participants signed informed consent form prior to their inclusion in the study.

  • Conflict of interest

    The authors have stated explicitly that there are no conflicts of interest in connection with this article.



The Berlin Questionnaire (BQ) and Epworth Sleepiness Scale (ESS) are two of the widely used screening instruments for subjects suffering from sleep disorders.


To determine the predictive accuracy of the BQ and ESS in the subjects who were admitted to our sleep clinic, using overnight polysomnography as the ‘gold standard’.


The BQ and ESS were performed to 1450 subjects hospitalized in our sleep clinic for polysomnographic evaluation.


One thousand two hundred thirty of 1450 subjects (84.8%) had apnea–hypopnea index (AHI) ≥ 5, and 70.5% of them were classified as being at high risk of sleep apnea with BQ and 45.9% of them were classified as having excessive daytime sleepiness with ESS. Being in the high-risk group with the self-reported, BQ predicted an AHI ≥ 5 with a sensitivity of 0.73 and a specificity of 0.44, vs a sensitivity of 0.46 and a specificity of 0.60 with the self-reported ESS. Sensitivity of BQ (0.80) was highest when we selected the cut-off value of AHI as 30. When we evaluated the predictive accuracy of BQ and ESS together, specificity of both instruments as 0.72 at AHI cut-off value of 5 was found. AHIs were significantly correlated with the scores in each category and the total scores of BQ (P < 0.0001).


The BQ is a poor predictor of obstructive sleep apnea (OSA) in subjects admitted to our sleep clinic. BQ and ESS together may be used to detect patients with low risk for OSA.