The Usefulness of the Berlin Questionnaire as a Screening for Obstructive Sleep Apnea in a Sleep Clinic Population

Kang, Hyeon Hui; Kang, Ji Young; Lee, Sang Haak; Moon, Hwa Sik

Abstract

OBJECTIVES
The Berlin Questionnaire (BQ) has been used to help identify patients at high risk of having sleep apnea in primary care. But it has not been validated in a sleep clinic for Korean patients. The aim of this study is to evaluate the usefulness of the BQ as a screening tool for obstructive sleep apnea (OSA) for Korean patients in a sleep clinic.
METHODS
The BQ was prospectively applied to 121 subjects with OSA suspicion who visited to our sleep clinic. All subjects performed overnight polysomnography. OSA was defined as an apnea-hypopnea index (AHI) > or =5. We investigated the sensitivity, specificity, positive and negative predictive values of the BQ according to severity by AHI.
RESULTS
In 121 subjects, 73.6% were males, with a mean age of 48.8+/-13.0 years. Twenty-five (20.6%) patients did not have OSA (AHI<5), 30 (25%) patients had mild OSA (AHI> or =5 and <15), 26 (21.4%) had moderate (AHI> or =15 and <30), and 40 (33%) had severe OSA (AHI> or =30). The BQ identified 69.4% of the patients as being at high risk for having OSA. The sensitivity and specificity of the BQ were 71.9% and 40%, for AHI> or =5, 75.8% and 38.2% for AHI> or =15, 77.5% and 34.6% for AHI> or =30, respectively. The positive and negative predictive values of the BQ were 82.1% and 27.0% for AHI> or =5, respectively. Positive and negative likelihood ratios were 1.2 and 0.7, and the overall diagnostic accuracy of the BQ was 65.3%, using an AHI cut-off of 5.
CONCLUSION
Due to modest sensitivity and low specificity, the BQ does not seem to be an appropriate tool for identifying patients with obstructive sleep apnea in a sleep clinic population.