Assessment - History

History of patients with suspected OSA includes sleep behaviours (snoring, arousals, sleeping position), sleep quantity and quality including nocturnal and daytime complaints and physical symptoms, hypertension, cardiovascular disease, type 2 diabetes, thyroid disease, depression, and family history of OSA or CPAP use.

It is important to exclude other causes of daytime sleepiness such as sleep restriction or sleep disorders that require separate advice and management (e.g. insomnia, restless legs syndrome/periodic limb movement).

History taking should include the following variables; sleep quantity / total sleep time, sleep quality / sleep fragmentation / sleep behaviours (e.g., bed and waking times, caffeine and alcohol consumption) / nocturnal awakenings, daytime (e.g. sleepiness) and nocturnal complaints and physical symptoms, and time evolution, severity, circumstances and psychosocial impact of the complaints, possible coexisting disease including hypertension (especially in younger patients), cardiovascular disease (especially atrial fibrillation and heart failure), cerebrovascular disease (stroke and transient ischemic attacks), diabetes mellitus, thyroid disease, and family history of OSA or continuous positive airway pressure (CPAP) use.

History taking from the patient’s bed partner (if present) is an important part of the assessment process, as patients are often not aware of their symptoms, especially snoring and apnoeas.

Daytime sleepiness, a symptom of some but not all patients with OSA, is very common in the general population and therefore other causes should be excluded. The different causes of daytime sleepiness include poor quality (fragmented sleep) and quantity of sleep (sleep restriction), insomnia, circadian rhythm disorders (including shift work sleep disorder), depression, narcolepsy, hypothyroidism, restless legs syndrome/periodic limb movement disorder, sedative medication, a side effect of medication not used for sedation (e.g. some of the antidepressants/anti-epileptics/antipsychotics etc.), stimulants such as caffeine, theophylline, amphetamines, beta-blockers, selective serotonin reuptake inhibitors (SSRIs), excess alcohol intake, neurological conditions including dystrophica myotonica, previous encephalitis, previous head injury, parkinsonism, and idiopathic hypersomnolence.

Table. OSA daytime and nocturnal complaints and physical symptoms¹