1.1 The need for the guideline

Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) can be defined as the coexistence of excessive daytime sleepiness with irregular breathing at night. The abbreviations OSAS and OSA are used widely and synonymously with OSAHS, however this guideline will use only the latter. OSAHS is a significant public health problem and there is a large and increasing demand for sleep service facilities due to the high prevalence and growing public awareness of sleep disorders, including OSAHS. A conservative estimate of the prevalence of OSAHS in middle-aged men (30-65 years) is in the range 0.3–4%, with most studies giving a prevalence of 1-2% which is a similar prevalence to Type 1 diabetes and approximately double that of severe asthma.^{1, 2, 3, 4} The prevalence of OSAHS in middle-aged women has been less well studied but is probably about half that in males, at around 0.5–1%.²

A significant variation exists across the UK, both in the availability of diagnostic tests and the provision for treatment of sleep-disordered breathing.

The consequences of untreated sleep apnoea on daily function are multiple and include increased daytime sleepiness, impairment of cognitive function, mood and personality changes.⁵ Sleep apnoea is also associated with a reduction in quality of life⁶ and there can be adverse effects on others including impaired relationships between spouses and partners.⁷ Symptoms of sleepiness and impaired concentration resulting from untreated sleep apnoea are thought to have serious consequences during activities where reduced alertness is dangerous, such as driving, leading to an increased risk of road traffic accidents.^{8, 9} There is objective evidence for a 1.3 to 12-fold increase in accident rates among patients with OSAHS.^{2, 8, 10} Sleepiness at the wheel is estimated to cause about 20% of road accidents on major highways, although it is unclear how many of these are due to OSAHS. These accidents usually occur at high speed, without avoidance reactions and are associated with serious injuries and a high mortality rate.^{9, 11, 12}

The estimated cost to society of a fatal road traffic accident is approximately £1,250,000, making it highly desirable to produce a national guideline which may help to reduce the medical, social and financial costs of excessive sleepiness.¹³

1.2 Remit of the guideline

This guideline presents evidence based recommendations for the diagnosis and management of obstructive sleep apnoea/hypopnoea syndrome in males and females over 16 years. It is not intended to exhaustively cover all causes of excessive daytime sleepiness in adults nor does it deal with central sleep apnoea nor specifically with snoring. The guideline aims to produce recommendations which can be used to aid patients, general practitioners (GPs), secondary care physicians and surgeons to recognise the symptoms of this common disorder, to prioritise referral requests, to understand how sufferers may be investigated and which treatment modalities are currently available.

1.3 Statement of intent

This guideline is not intended to be construed or to serve as a standard of medical care. Standards of care are determined on the basis of all clinical data available for an individual case and are subject to change as scientific knowledge and technology advance and patterns of care evolve. These parameters of practice should be considered guidelines only. Adherence to them will not ensure a successful outcome in every case, nor should they be construed as including all proper methods of care or excluding other acceptable methods of care aimed at the same results. The ultimate judgement regarding a particular clinical procedure or treatment plan must be made by the doctor, following discussion of the options with the patient, in light of the diagnostic and treatment choices available. However, it is advised that significant departures from the national guideline or any local guidelines derived from it should be fully documented in the patient’s case notes at the time the relevant decision is taken.

1.4 Review and updating

This guideline was issued in 2003 and will be considered for review in 2006, or sooner if new evidence becomes available. Any updates to the guideline will be available on the SIGN website: www.sign.ac.uk