A common test used to diagnose obstructive sleep apnea may miss the condition in Black patients, potentially impacting important treatment decisions.Sleep studies often use pulse oximeters — small devices that measure blood oxygen levels — to help determine the severity of sleep apnea.In the new study, oxygen-based scoring counted roughly 20 percent fewer breathing events in Black participants than in white participants.But heart-rate-based scoring showed no comparable racial difference.The first author says the findings have “potential implications for diagnosis and severity classification.”Earlier research shows pulse oximeters may be less accurate on darker skin. The study can’t prove the device is the cause, though.The researchers say a normal or borderline result in Black patients should be read carefully when symptoms or other conditions strongly suggest sleep apnea.That means loud snoring, gasping at night, daytime exhaustion, or conditions like high blood pressure or diabetes. Source: American Journal of Respiratory and Critical Care Medicine.Author Affiliations: Brigham and Women's Hospital, Harvard Medical School.Sign up for our weekly HealthDay newsletter