Epidemiology of sleep apnoea/hypopnoea syndrome and sleep-disordered breathing.

Epidemiological studies have revealed a high prevalence of sleep-disordered breathing in the community (up to 20%). A subset of these patients has concurrent symptoms of excessive daytime sleepiness attributable to their nocturnal breathing disorder and is classified as having obstructive sleep apnoea/hypopnoea syndrome (4-5% of the middle-aged population). There is strong evidence for an association of sleep apnoea with cardiovascular and cerebrovascular morbidity, as well as adverse public health consequences. Treatment and diagnosis have remained largely unchanged over the past 25 yrs. In moderate-to-severe obstructive sleep apnoea/hypopnoea syndrome, treatment with continuous positive airway pressure has been shown to be effective. Questions remain as to how to screen patients with sleep-disordered breathing. Should time-consuming diagnostic procedures with high sensitivity and specificity be employed, or should simpler methods be applied for screening populations at risk, e.g. in the primary care sector?