The purpose of this study is to validate the Berlin questionnaire and STOP-BANG (snore, tired, obstruction, pressure, body mass index (BMI), age, neck, gender) as effective screening tools for Chinese subjects who are suspected to have obstructive sleep apnea (OSA).

Obstructive sleep apnea (OSA) is a common sleep related breathing disorder associated with excessive daytime sleepiness and cardiovascular disease. It is prevalent in both western (4-26%) and eastern countries (4-19%). In recent studies, it has been estimated that at least 70-80% of middle aged individuals with sleep apnea are undiagnosed and untreated. The prevalence of undiagnosed OSA subjects within the community suggests the need for a greater awareness and a high index of suspicion of this disease entity as well as its associated short- and long-term comorbidities.

A reliable and easy-to-use screening questionnaire is required for efficient prediction of OSA and treatment arrangement. It would be helpful to prioritize patients who require sleep study according to the probability of suffering from sleep apnea. It reduces the use of sleep study for those with low probability of having OSA, but giving treatment to those who are with more severe OSA first. Meanwhile, it enhances the cost effective management of disease especially with limited resources in our society.

Inclusion Criteria:

a. No known history of any sleep disorder

Exclusion Criteria:

1. History of heavy alcoholism ( ≥ 3 times / week)
2. Underlying pulmonary diseases
3. Recent upper respiratory tract infection in the past one week
4. Unstable medical conditions
5. Pregnancy
6. History of psychiatric illness

Subjects who are referred to have a diagnostic polysomnography (PSG) will be recruited from the Sleep Disorders Centre, Department of Medicine, Queen Mary Hospital.