Prevalence of Obstructive Sleep Apnoea in Sleep Referrals and Related Medical Conditions in a Local Chest Unit in Hong Kong

Objective: To understand obstructive sleep apnoea (OSA) epidemiology and associated comorbidities in a Chest Unit in Hong Kong, and to better understand sleep referrals to enhance screening assignment. Design: A prospective, observational case-series study from a Chest Unit in Hong Kong. Subjects: Patients, aged ≥17 years old or older and referred to Wong Tai Sin Hospital for polysomnography, were recruited from the 15th of September 2022–31st of January 2023. Methods: Demographic, anthropometric, and phenotypic characteristics were collected. Questionnaires (Epworth Sleepiness Scale [ESS], Patient Health Questionnaire-9 [PHQ-9]) were completed and polysomnography was performed on the following night. The presence of OSA was defined as apnoea–hypopnoea index (AHI) ≥5 events·h -1. Results: A total of 303 patients were recruited. The prevalence of OSA amongst the referred patients was 91%, and ischaemic heart disease, diabetes, and hypertension accounted for 16.3%, 34.8%, and 63.4%, respectively. In addition, 43.4% of patients fulfilled the definition of depression according to their PHQ-9 score (≥5). Conclusion: This observational study showed that the appropriateness of referrals for sleep tests was adequate, with 91% of patients having OSA. The majority of them are overweight or obese and presented with hypertension, diabetes, and mild depression, and excessive daytime sleepiness.