Rethinking AASM guideline for split-night polysomnography in Asian patients with obstructive sleep apnea

Split-night polysomnography (SN-PSG) provides both a diagnosis and titration of continuous positive airway pressure over a single night in patients with suspected obstructive sleep apnea (OSA). However, in Asian patients, the diagnostic validity of American Academy of Sleep Medicine (AASM) guidelines for SN-PSG remains uncertain. Therefore, we examined whether the current criteria for SN-PSG are pertinent for Asian patients.

We investigated 134 consecutive patients who were diagnosed with OSA (apnea-hypopnea index (AHI) ≥ 5). We divided the raw data (full-night study) into two parts and compared the first 2 h of sleep with the full night of sleep to evaluate the diagnostic precision and accuracy of the first 2 h of sleep.

No difference in AHI was observed between the first 2 h and the full night of sleep. A significant correlation of AHI was observed between the first 2 h and the full night of sleep for severe OSA patients (AHI ≥ 30). A correlation coefficient of AHI was higher by the criterion of AHI ≥ 30 than by the criterion of AHI ≥ 40 (r = 0.831 and r = 0.778, respectively), which is the current AASM criterion for SN-PSG. Moreover, the criterion AHI ≥ 30 showed better diagnostic accuracy than the criterion AHI ≥ 40 (89.3 and 88.7 %, respectively).

This study found possible evidence supporting different diagnostic criteria for SN-PSG in Asian population. We suggest further studies in other Asian populations to confirm these findings.