New pulse oximeter bias findings muddy the path to fixes for darker skin tones

A prospective FDA-funded study called EquiOx measured 631 patients with pulse oximeters against arterial blood gases to quantify bias across skin tones. The preprint results were surprising: they suggested pulse oximeters may underestimate oxygen levels in darker-skinned patients, while also showing higher readings in darker versus lighter skin tones, a combination that undermines a simple universal correction. With the study not yet peer-reviewed, clinicians face unclear guidance on how to adjust readings, and questions remain about study design and applicability. Funding gaps and political pressures around health disparities add to delays in final FDA guidance and larger multi-site research plans, though researchers are pursuing broader datasets and international collaboration (e.g., Uganda) to resolve the issue.