Study Uncovers How Medical Device Bias Could Lead to 5-Hour Delays in COVID-19 Treatment for Black Patients
Sep 29, 2022
Sutter Health

Novel Research from Sutter Health Highlights the Ongoing Need to Understand & Help Correct Racial Bias in Every Corner of Medicine

SACRAMENTO, Calif. – A new study released today from Northern California-based Sutter Health linked bias in the device used to measure blood oxygen, the pulse oximeter, to impacts on COVID-19 clinical care. The research revealed that pulse oximeter errors could have led Black patients to face a 4.5-hour delay in COVID-19 treatment.

Blood oxygen level, most commonly assessed using the pulse oximeter, has been central to CDC treatment guidelines for COVID-19.The pulse oximeter was previously found to be less accurate in patients with darker skin, and a recent JAMA study revealed this resulted in a lower likelihood for COVID-19 treatment eligibility among several racial and ethnic groups. Sutter’s latest analysis helps quantify the clinical impact of differential pulse oximeter accuracy on non-Hispanic Black patients suffering from COVID-19 – namely, that device inaccuracy was associated with delayed treatment for COVID-19 when compared with expected treatment under accurate blood oxygen measurement.

The study, led by researchers at Sutter’s Institute for Advancing Health Equity (IAHE), and conducted in collaboration with clinicians and researchers from the Roots Community Health Center and the University of California San Francisco, found that Black COVID-19 patients could have delayed treatment due to the device’s inability to precisely read blood oxygen levels on darker skin. The analysis uncovered that overestimated blood oxygenation was associated with the following delays in COVID-19 care for Black patients:

  • Increased time to supplemental oxygen treatment (4.5 hours)
  • Increased time to dexamethasone treatment (37 minutes)
  • Lower hospital admission probability (3.1%)
  • Lower probability of receiving dexamethasone treatment (3.1%)
  • Lower probability of receiving supplemental oxygen treatment (4.2%)

“Oxygen is one of the most frequently administered and essential medical therapies, and while flaws in the pulse oximeter device were raised during the pandemic, just how it actually affected patients remained unknown – until now,” said Stephanie Brown, M.D., MPH, clinical lead for the IAHE.

Industry analysts expect the use of the pulse oximeter to significantly increase in the coming years, making it critically important to continue studying and working to resolve this bias. The study’s authors identified several opportunities to address the device bias including revising the current guidelines for testing the device’s accuracy and for its use in the field, particularly when other clinical factors are inconsistent with a patient’s pulse oximetry measurements. The results also emphasize the need for additional investigation of the device given the broader implications beyond COVID-19 and its potential to exacerbate disparities for a wide variety of conditions that rely upon blood oxygenation readings to inform clinical decision-making, like emphysema and chronic obstructive pulmonary disease, or COPD.

“The findings underscore the fact that bias is not only human– it can be engrained in the devices and tools clinicians rely on, too. To build a more equitable healthcare system we must continue to not only uncover where bias exists in medicine, but also work to understand its impact on clinical outcomes and how it can be corrected. This is good medicine,” Dr. Brown added.

The IAHE had previously analyzed the disproportionate impact of the pandemic on communities of color using electronic health record (EHR) data. Its latest research insights are an important extension of the original work. It reveals how bias embedded in the pulse oximeter device may have exacerbated existing disparities.

“This study confirms our suspicions that other factors could be contributing to the disparities in deaths and severity of illness related to COVID, and delays in care for people of color in our community,” said Noha Aboelata, MD, CEO of Oakland, Calif.-based Roots Community Health Center and co-author of the study. “We thank Sutter for their collaboration in responding to our shared concerns and studying the impact of pulse oximeters on care decisions. Despite this and previous studies, these devices remain in use. It’s time we all demand technology that doesn’t discriminate.”

The pulse oximeter findings are just the tip of the iceberg. This latest research is part of Sutter’s continued commitment to eliminating health disparities within its system and beyond by generating knowledge and driving a conversation around solutions. Through the IAHE, Sutter is taking a comprehensive, 360-degree approach to uncover and address racism within medicine, including:

  • Eliminating the race-based e-GFR Calculation: Sutter is now one of the largest systems nationwide to eliminate race-based eGFR reporting, helping correct an industry-wide issue to make earlier diagnosis, treatment and transplant list placement for thousands of Black patients possible.
  • Launching the Health Equity Innovation Lab for Maternal Health Equity: As a continuation of the successful track record of addressing maternal health disparities, Sutter has announced the launch of an innovation center dedicated to addressing racial inequities in childbirth by advancing research and solutions.
  • Examining How Bias Impacts Algorithms: It’s not just humans or devices – bias is also automated within medicine. Sutter is examining the algorithms used to assess factors such as sepsis risk, hospital readmission risk and palliative care eligibility, and algorithms used for pulmonary function testing.
  • Addressing Unconscious Bias: For years a key component of Sutter’s health equity work has been increasing awareness and knowledge among Sutter clinicians, employees and system leaders of the importance of culturally competent care and how to provide it. Building upon these efforts, Sutter is working alongside the California Medical Association, Physicians for a Healthy California, the California Primary Care Association and others to host a symposium on Oct. 14 that will convene clinicians, policymakers scientists and community leaders to review the harmful impact of unconscious bias, policies that have been introduced and enacted, and explore how unconscious bias mitigation strategies can be evaluated for effectiveness. The goal of the symposium will be to develop evidence-based standards and a framework for unconscious bias mitigation strategies that includes a way to measure their impact and can be implemented across the state.

“Our research is just one part of an ongoing, multi-layered process that requires collective action across the healthcare industry to ensure that we are creating targeted interventions that take underrepresented groups into account,” said Kristen M.J. Azar, R.N., MSN/MPH, FAHA, scientific medical director at IAHE. “By leaning on the benefits of Sutter’s integrated network, our Institute is uniquely positioned to conduct research, analyze data and continue to drive a conversation to change how we practice medicine. Ultimately, our goal is to eliminate health inequities and drive better health outcomes for patients in our network and nationwide.”

The full IAHE study can be seen in the American Journal of Epidemiology:

To find out more about Sutter Health’s work to advance health equity, please visit:

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