Obstructive sleep apnea (OSA) is a common sleep disorder in the U.S. affecting tens of millions, with estimates ranging from 25 to more than 80 million adults. However, most remain unaware they have the condition, which can cause severe health risks like high blood pressure, heart disease and impaired daytime function. OSA is often diagnosed using pulse oximetry, a non-invasive method for monitoring blood oxygen saturation. However prior studies have shown that pulse oximeters have the potential to overestimate oxygen saturation, and these instruments miss episodes of hypoxia at a greater rate in people with darker skin, particularly Black, Hispanic and Asian individuals, when compared to white individuals.

Two definitions are currently used by the American Academy of Sleep Medicine to determine OSA: a 30% airflow decrease with a 3% oxygen desaturation or EEG arousal (abrupt shift in brainwave frequency) or a 30% airflow decrease with a 4% oxygen desaturation. The Centers for Medicare and Medicaid Services and many commercial payers use only the 4% rule to confirm OSA, which may limit patient access to sleep apnea treatment.

A new study by researchers at Boston University Chobanian & Avedisian School of Medicine has found that despite known limitations of pulse oximetry associated with skin tone, no racial differences in the diagnosis of OSA were seen in this group. However, female patients had lower odds of meeting the 4% threshold, suggesting a potential barrier to treatment for women.