A retrospective cohort study conducted by Tianshi David Wu, MD, MHS, and colleagues at Baylor College of Medicine in Houston revealed that an overestimation of oxygen saturation by pulse oximetry resulted in delayed delivery of COVID-19 therapy, along with an unrecognized need for therapy among Black patients. The study involved over 24,000 patients who had concurrent pulse oximeter saturation (SpO2) and arterial oxygen saturation (SaO2) measurements. The findings showed that patients with an initially unrecognized need for COVID therapy were 10% less likely to receive therapy, and they had higher odds of readmission. Surprisingly, race did not play a significant role in these outcomes.
The study findings emphasize the impact of pulse oximeter inaccuracy on clinical decision-making and patient outcomes. Previous research has shown variability in the accuracy of pulse oximeters, and this study further highlights the multifactorial nature of pulse oximeter accuracy, extending beyond skin pigmentation. Inaccurate pulse oximetry can lead to delays in receiving appropriate medical treatment for COVID-19, affecting patient outcomes.
One notable finding of the study was that Black patients, even without an immediate need for COVID therapy, were more likely to have pulse oximetry values that did not indicate a need for therapy compared to white patients. This indicates that pulse oximetry accuracy disproportionately affects Black patients. However, the study also revealed that both Black and white patients experienced similar delays in receiving COVID-19 medication due to pulse oximeter inaccuracy. This suggests that racial bias in pulse oximeter accuracy is a significant factor in the treatment differences seen between Black and white patients.
Challenges in Representativeness of Patient Samples
William Padula, PhD, of the University of Southern California, raised a crucial point regarding the representativeness of patient samples in previous pulse oximeter calibration trials. He highlighted that the calibration studies primarily included patients who were not from underrepresented minority groups or individuals with darker skin tones. As a result, the efficacy of pulse oximeters demonstrated in clinical trials may not hold true when applied to real-world patient populations. This highlights the need for health systems to allocate more resources to ensure accurate diagnosis and equitable care for all individuals.
The Importance of Multiple Diagnostic Tools
To mitigate the limitations of pulse oximetry accuracy, it is crucial to use multiple diagnostic tools for accurate diagnosis and treatment administration. While sensory technology, such as pulse oximeters, has undoubtedly improved healthcare efficiency, it should not be solely relied upon for making important medical decisions. Other data points and diagnostic tools should be incorporated to ensure comprehensive and equitable care for all individuals. This is particularly important as health systems prioritize health equity and strive to address healthcare disparities.
Limitations of the Study
The researchers acknowledge certain limitations of their study. Other factors, such as hospital staffing, therapy availability, and practice patterns, may have also influenced the time to treatment administration. Additionally, the study’s exclusion of patients receiving oxygen therapy as a result of dyspnea, potential deviation from established guidelines at provider locations, and the use of self-reported race and ethnicity as a substitute for actual skin tone may have limited the generalizability of the study findings.
The study highlights the detrimental impact of pulse oximeter inaccuracy on COVID-19 therapy delivery and patient outcomes. The findings emphasize the need for healthcare providers to critically evaluate pulse oximetry values and not solely rely on them for medical decision-making. Moreover, the study sheds light on the racial disparities in pulse oximetry accuracy, with Black patients experiencing a greater likelihood of inaccurate readings. Moving forward, it is crucial to prioritize health equity and ensure that diagnostic tools and healthcare interventions are effective and equitable for all patient populations, irrespective of race or ethnicity.