Reducing barriers to the diagnosis of obstructive sleep apnoea in patients with severe mental illness

To the Editor

Obstructive sleep apnoea (OSA) is common in people with severe mental illness (SMI) and has been attributed to the high prevalence of obesity caused by antipsychotic medication and lifestyle factors (Myles et al., 2016).

OSA is associated with cardio-metabolic morbidity and mortality, which contributes to the loss of life expectancy in people with SMI (Myles et al., 2016). Other features of OSA include cognitive impairment, daytime sleepiness, impaired daytime functioning and reduced quality of life (Myles et al., 2016). Successful treatment of OSA may therefore be important in improving physical health, functioning and quality of life in people with SMI. Although routine screening for OSA is recommended in the RANZCP Clinical Practice Guidelines for Schizophrenia and Related Disorders, it is often under-diagnosed and under-treated in people with SMI (Galletly et al., 2016). The pathway to OSA management can be prolonged, inconvenient and expensive, and drop out is common (e.g. Myles et al., 2018). Barriers include long wait-times for sleep clinic appointments and unwillingness of some patients to undergo a polysomnogram (PSG) in the hospital’s sleep laboratory.

To reduce some of these barriers, we have established a one-bed ‘sleep laboratory’ on our Mental Health Rehabilitation Unit. Many patients feel more comfortable and supported with familiar staff and surroundings compared to the unfamiliar environment of the hospital sleep laboratory.

Clients of the service identified as at ‘high risk’ of OSA on one or more of the STOPBang, Berlin Questionnaire or OSA50 screening tools, AND the Epworth Sleepiness Scale OR on the basis of clinical suspicion, are offered the opportunity for admission to the unit for a minimum two-night stay as an alternative to the conventional sleep laboratory setting. Following a night to acclimatise, the PSG is performed using a Phillips Alice PDX Portable Diagnostic System, set-up by a sleep technician.

To date, more than 20 clients have completed a sleep study on the ward without issue. Staff and clients have expressed overall satisfaction with the admission and testing process. Formal evaluation will be undertaken to further assess the effectiveness of utilising a sleep laboratory in routine mental health settings to reduce the barriers to managing OSA in people with SMI.

The MHRU sleep laboratory does not eliminate all barriers to diagnosis and treatment of OSA in the SMI population, but we are encouraged that we are developing novel ways of assisting clients to identify and manage this important problem.