Use of a limited-channel device for obstructive sleep apnoea diagnosis in a tertiary sleep disorders centre

A major impediment to the provision of obstructive sleep apnoea (OSA) treatment is reliance on labour-intensive and costly laboratory-based polysomnography (PSG).

To investigate if measurement of oximetry and nasal flow through the ApneaLink device (AL) could identify patients with moderate-severe OSA among those referred for PSG to a tertiary sleep service.

New referrals to The Prince Charles Hospital Sleep Disorders Centre were assessed for suitability. Demographics, anthropometrics, Epworth Sleepiness and OSA50 scores were collected. Exclusion criteria included age <18 years, pregnancy, significant cognitive impairment, poorly controlled psychiatric disorder, domiciliary oxygen and prior OSA treatment. Participants underwent concurrent type 1 PSG and AL assessments.

One hundred participants had a mean age of 55 years (standard deviation 17) and were 49% male. Forty-eight (48%) had moderate-severe OSA on PSG. Composite variable AL 3% oxygen desaturation index ≥16 and AL apnoea-hypopnoea index (AHI) ≥15 had receiver operator characteristic area under the curve of 0.87, sensitivity of 80% and specificity of 94% for PSG AHI ≥15. The three false-positives seen with this composite variable had PSG AHI 11-14 and Epworth Sleepiness Score 6-17. The various composites of AL, anthropometric and questionnaire variables did not improve the AUC or specificity but did improve sensitivity.

AL is useful in the diagnosis of moderate-severe OSA in patients referred to a tertiary sleep disorders centre. This could lessen reliance on PSG, expedite OSA care, lead to significant cost savings and make diagnosis of OSA more available in non-urban areas.