A respiratory therapy panel of the FDA Medical Devices Advisory Committee published a discussion paper on improving the evaluation of pulse oximeters to take skin pigmentation into account. The agency asked for public feedback regarding an Approach for Improving the Performance Evaluation of Pulse Oximeter Devices Taking Into Consideration Skin Pigmentation, Race, and Ethnicity.
AARC responded by submitting comments in advance of a virtual public meeting scheduled to be held on February 2, 2024, so that our voice may be heard by the Advisory Committee prior to their open discussions.
The indirect measure of arterial hemoglobin oxygen saturation (SaO2) using a pulse oximeter (SpO2) is ubiquitous in healthcare systems. Recently, there has been increased attention to the imprecision of SpO2 when compared to SaO2. Moreover, there are concerns that the level of skin pigmentation contributes to inaccuracies in SpO2, which has real world implications for patient care. This might lead to delays in escalation of care, incorrect or missed diagnoses, and failure to qualify patients for life-extending home oxygen therapy.
Of great importance is that inaccuracies of SpO2 may also lead to healthcare disparities and access to care issues. For example, we know that SpO2 is often overestimated in people with darker pigmented skin leading to a missed diagnosis of hypoxemia, so called ‘occult hypoxemia,’ where hypoxemia is present despite a normal SpO2. These missed diagnoses may often occur in people who are already underserved due to factors associated with social determinants of health. The lack of accurate SpO2 may further exacerbate healthcare disparities in a variety of ways including denial of access to home oxygen therapy when needed. However, it should also be appreciated that these inaccuracies are present for all individuals and can lead to undetected hypoxemia regardless of skin pigmentation.
AARC Recommendations to the FDA Advisory Committee
The AARC recommends the FDA require the following to address the accuracy of measurement, and to address the bias in pulse oximetry measurement among those with darkly pigmented skin. Our intention is to improve pulse oximetry accuracy – as accuracy is key for patient care. It is important to appreciate that inaccuracies in oximetry measurements occur across skin tones. Perfusion, temperature, and many other physiologic factors can lead to inaccuracies in the ability of SpO2 to accurately reflect SaO2.
Recommendation 1. Require that pulse oximetry device clinical trials be conducted in the environment in which they will be used. For example, pulse oximetry devices are used thousands of times every day in intensive care units around the country, but most, if not all, clinical trials are performed in a laboratory setting. Studies show that clinical trials performed in laboratory settings differ from clinical trials performed in the field.
Recommendation 2. Clinical trial participants should match the diversity of the population. For example, as of 2020, approximately 60% of the US population is white, 19% is Hispanic or Latino and12% are Black or African American.4 A clinical trial should be designed with the same ratios applied to the trial cohort. Any clinical trial should also include the appropriate ratios for other populations including Asians and American Indian.
Recommendation 3. Require the use of the Monk Skin Tone test, Fitzpatrick score, or equivalent in all clinical trials. The need for data collection to be objective is emphasized here as most race information is self-reported.
Recommendation 4. Clinical trials should evaluate pulse oximeter measurements for various disease states,not only for healthy individuals in the laboratory setting.
Please see the AARC’s full comment letter here.