Letter to the Editor

I work in the UK National Health Service that cannot afford unnecessary investigations. Earlier this year you published an article, entitled European Guidelines for the accreditation of Sleep Medicine Centres , which I read with growing concern. The assumption of this article is that proper sleep medicine centres do routine polysomnography (PSG) on their patients and, if you do not, you cannot be a proper sleep medicine centre. This is implicit in the stated requirements of PSG equipment for each bed before a sleep laboratory can be accredited. In addition, there were several further completely unsubstantiated requirements, such as the sleep unit being an independent entity, and the staff totally dedicated to sleep laboratories, with no other duties. This document reveals the wide gulf between current clinical practice and academic practice, a problem present in the USA as well (Kushida et al., 2006). The vast majority of patients now presenting to sleep services are being seen and investigated for possible sleep apnoea (Punjabi et al., 2000). There is no evidence that PSG is the superior approach to making this diagnosis, or for monitoring CPAP initiation, in fact the evidence is in favour of much simpler approaches (Bennett et al., 1998; Chakravorty et al., 2002; Dingli et al., 2003; Douglas et al., 1992; Johnson et al., 2004; Masa et al., 2004; Nixon and Brouillette, 2002; Vazquez et al., 2000; West et al., 2006; Whitelaw et al., 2005). Thus, there is no justification for routinely employing PSG when investigating for possible sleep apnoea, or when initiating CPAP. One of the most skilled aspects of sleep apnoea work is the provision of a nasal CPAP service where there is good evidence that extra skilled input does improve outcomes (Engleman and Wild, 2003; Golay et al., 2006; Hoy et al., 1999; Jean et al., 2005; Kirk and O Donnell, 2006), this area of a sleep clinic s work receives no acknowledgement, and again reveals the academic bias of the writers. Many of the other diagnoses made in a sleep clinic do not need PSG either, for example, narcolepsy, PLMS, depression, phase displacement syndromes, poor sleep hygiene, etc., a view shared by others (Douglas, 2003; Kryger, 2002; Nixon and Brouillette, 2002). Narcolepsy is a diagnosis made on history, HLA typing (to exclude the diagnosis) and multiple sleep latency test (Aldrich et al., 1997; although not definitive); and soon probably by CSF orexin levels (Baumann et al., 2006). Periodic leg movements during sleep can be diagnosed with alternative approaches such as actigraphy (King et al., 2005) and video recordings. REM behaviour disorder is usually clear on history (Leo, 2003) and may be missed on one sleep study anyway, but remains an area (along with nocturnal epilepsy) where for medico-legal reasons PSG may be required. This is likely to remain an extremely small part of a sleep laboratory s work and does not justify the routine use of PSG. Indeed, the document accepts that a sleep medicine centre may need to refer some patients to other units for other specific assessments where facilities are not available in house. Polysomnography has an important part to play in research. Documenting sleep stages and arousals are important end points in trials of therapy in many sleep disorders, particularly with drugs that may affect sleep architecture. However, even in research settings, simpler techniques may allow more definitive studies with greater numbers and hence power, but at lower cost (Jenkinson et al., 1999; Pepperell et al., 2002). Thus, the insistence on the availability of routine polysomnographic facilities in the requirements for accreditation of a clinical sleep medicine centre is, at best, simply archaic and non-evidence-based and, at worst, protectionist and an example of unjustifiable income generation. In my view it is particularly unethical to go on insisting on this more expensive (Ghegan et al., 2006) and unnecessary investigation when many families (Himmelstein et al., 2005) and most health services are crippled by rising healthcare costs (Tu, 2004), particularly when there exists clear evidence of under diagnosis (Tran and Wallace, 2005). To follow the advice of these guidelines would have extremely detrimental effects on most country s abilities to investigate the extremely prevalent condition of sleep apnoea. This would clearly be extremely bad news for patients unable to afford private care. I would challenge those who insist that PSG is the gold standard in the area of sleep medicine to provide the evidence that it is a superior and ethical diagnostic tool compared with the much cheaper alternatives that are already in use in the many sleep laboratories that have moved on and accepted the evidence before them.