Dr. Au is the person-in-charge of the paediatric sleep diagnostic and research laboratory in the Prince of Wales Hospital. His research has centered around sleep-disordered breathing and sleep deprivation in children and adolescents. Particularly, he has been investigating the cardiovascular and neurocognitive complications of obstructive sleep apnea (OSA) and the treatment responses, the natural history of OSA from childhood to adulthood, the familial aggregation and heritability of childhood OSA, the screening and diagnosis of OSA, and the epidemiology of OSA in different paediatric age groups. Besides, he runs a regular training course for respiratory and sleep medicine trainees and research personnel involved in the management of paediatric sleep problems. He has been frequently invited to lecture and provide educational workshops in a variety of sleep conferences both locally and in mainland China.