for people ages 18 years and up (full criteria)
at San Francisco, California
study started
completion around
Principal Investigator
by Philip Bickler, MD, PhD
Headshot of Philip Bickler
Philip Bickler



This is a prospective observational study designed to quantify and understand errors in pulse oximetry in hospitalized patients in relation to their skin pigmentation. It is driven by three recent retrospective studies showing missed diagnosis of hypoxemia in patients across a spectrum of skin pigmentation, defined as blood SaO2 <90% when their pulse oximeter reads 92% or greater.

Official Title

Prospective Clinical Study of Pulse Oximeter Errors in Hospitalized Patients With Varying Skin Pigmentation


This prospective study will overcome the limitations of earlier retrospective studies using three important study protocols:

  1. precise time-matching paired blood gas samples to stable periods of pulse oximeter readings
  2. objective quantification of skin pigmentation rather than using documented or self-reported race
  3. collection of high quality pulse oximeter tracing data, and identifying potential mediators of discordance of noninvasive and invasive measurements such as low perfusion states.

The primary aim is to quantify the bias in SpO2 measurements across skin pigmentation groups in a real-world setting against the gold standard of invasive measurements of arterial blood oxygen saturation measurements across categories of skin pigmentation. These data are essential to addressing health equity and patient safety for people of all skin pigmentations.


Hypoxemia, Pulse Oximetry, Skin Pigment, Hospitalized Patients, Hypoxia


You can join if…

Open to people ages 18 years and up

  • 18 years of age or older
  • hospitalized and at high risk of hypoxemia, defined as saturations < 90%,
  • patients with arterial line in place for clinical purposes

You CAN'T join if...

  • Profound anemia, defined as hemoglobin < 8 g/dl will preclude blood draws for research purposes
  • Known pregnancy
  • In custody of law enforcement officials


  • Zuckerberg San Francisco General and UCSF Health accepting new patients
    San Francisco California 94111 United States

Lead Scientist at UCSF

  • Philip Bickler, MD, PhD
    Professor, Anesthesia, School of Medicine. Authored (or co-authored) 137 research publications


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Study Type
Expecting 800 study participants
Last Updated