
When Machines Prescribe
Special | 17m 19sVideo has Audio Description, Closed Captions
Investigate medical algorithms in which the patient’s race drives decisions.
Doctors rely on computer programs to make decisions about diagnosis and treatment. Designed to weigh factors like symptoms, medical history, and test results to achieve the best possible outcomes for patients, some common medical algorithms were built using data based on old pseudoscience about racial differences. Investigate how their continued use has harmed the health of Black patients.
See all videos with Audio DescriptionADProblems with Closed Captions? Closed Captioning Feedback
Problems with Closed Captions? Closed Captioning Feedback
Major funding for this program is provided by the Robert Wood Johnson Foundation, the Doris Duke Foundation, the Alfred P. Sloan Foundation, and The California Endowment. Additional funding is provided...

When Machines Prescribe
Special | 17m 19sVideo has Audio Description, Closed Captions
Doctors rely on computer programs to make decisions about diagnosis and treatment. Designed to weigh factors like symptoms, medical history, and test results to achieve the best possible outcomes for patients, some common medical algorithms were built using data based on old pseudoscience about racial differences. Investigate how their continued use has harmed the health of Black patients.
See all videos with Audio DescriptionADProblems with Closed Captions? Closed Captioning Feedback
How to Watch NOVA
NOVA is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, Amazon Fire TV, Amazon Fire Tablet, Roku, Samsung Smart TV, and Vizio.
Buy Now

NOVA Labs
NOVA Labs is a free digital platform that engages teens and lifelong learners in games and interactives that foster authentic scientific exploration. Participants take part in real-world investigations by visualizing, analyzing, and playing with the same data that scientists use.Providing Support for PBS.org
Learn Moreabout PBS online sponsorship♪ ♪ ♪ ♪ NARRATOR: We routinely depend on doctors and medical institutions for our health.
But what if some of the guidelines used to diagnose and treat patients were based on bad science, resulting in actual harm?
♪ ♪ In 2022, Gregory Mumford learned from his doctor he had a kidney problem.
He says my kidney function was lowering little by little.
So, you know, that got me a little concerned, and I said, "Well, what's that about?
Why is it doing that?"
He says, "We might have to make some changes.
We might have to, you know, put you on dialysis for a while."
♪ ♪ NARRATOR: The kidneys' critical job is removing waste materials from the blood.
A dialysis machine would have to do the work of Gregory's kidneys, cleansing the blood before sending it back into his body.
PIPIER SMITH-MUMFORD: What was really challenging was, how does he get a transplant?
That, that was the goal.
Not to be on dialysis, but to get a more permanent solution.
♪ ♪ NARRATOR: For decisions like who should get a kidney transplant, doctors across many medical fields routinely use calculations that combine a patient's medical history with additional data.
These calculations are called clinical algorithms.
MICHELLE MORSE: A clinical algorithm is a tool that clinicians would use to really best understand their patient's specific diagnosis or treatment.
NARRATOR: According to the algorithm that Gregory's doctors used, if Gregory had the same test results but was white, he would have immediately qualified for a kidney transplant evaluation.
(whirring) But why would race be a variable in determining kidney function?
MORSE: There should be no reason why the physiological function of someone who's Black would look different than the physiological function of someone who's white.
NARRATOR: For centuries, Western medicine held that Black people were less sensitive to pain, had lower lung capacity, and denser muscle mass.
Science has shown these assertions to be baseless, but that doesn't mean they've been erased from modern medicine.
Most of us as clinicians are taught in medical school that race is a biologic variable.
And the problem is that it takes active effort to undo a lot of that teaching.
NARRATOR: But in many places, those efforts have begun.
DARSHALI VYAS: I began medical school in 2015.
We got the message loud and clear in the classroom that race is a social construct, that it's not meant to be used as a construct or a proxy for a biological difference.
MORSE: The tipping point for that understanding was the completion of the Human Genome Project that showed that there was more racial difference, genetically, within races than between races.
NARRATOR: In 2003, the Human Genome Project successfully sequenced the nearly three billion base pairs of DNA in the human genome.
MORSE: It's really in more recent decades that there's been broader agreement that race is not biological, and that it is actually a social classification.
VYAS: But as we made that transition gradually from the classroom to going to the wards and starting to see clinical medicine, we noticed a, a real tension between how we were taught about race and how we were seeing it being used by physicians and by our supervisors.
NARRATOR: Medical students' questions about the use of race in decision-making would soon spark a national controversy.
♪ ♪ MELANIE HOENIG: In 2016, I'm at Harvard Medical School.
And so the very first week of my new course, we are explaining about estimated GFR.
NARRATOR: GFR, or "Glomerular Filtration Rate," refers to how much work the kidneys are doing.
Estimated GFR, or eGFR, was the algorithm that nephrologists, or kidney doctors, used to calculate Gregory Mumford's kidney function.
HOENIG: And one of my students raised his hand and said, "Wait a second.
"Why would you have a formula "that provides a healthier value to the individuals at greatest risk of kidney disease?"
♪ ♪ I mean, I still remember that moment, because he was exactly right.
MAN: All right, now open your mouth and give me some deep breaths.
NARRATOR: A higher rate of kidney disease among Black Americans... Super.
NARRATOR: ...is largely attributed to social and environmental factors, like access to healthcare and poverty.
You're telling us that Black patients have a higher prevalence, a higher incidence, of kidney disease, and yet the formula makes them look like they have better kidney function for the same blood test as a non-African American patient.
How does that make sense?
NARRATOR: Before 1999, doctors were searching for a reliable alternative to the complex, expensive process of measuring kidney function, or GFR.
They wanted an estimate.
PAVLAKIS: So, we came up with this notion of estimated GFR.
NARRATOR: Essential to the eGFR calculation was creatinine, a waste product created by protein digestion and the normal breakdown of muscle tissue.
High creatinine levels in the blood are usually an indicator of poor kidney function.
PAVLAKIS: In 1999, what they had found was that, in the handful of patients that they looked at, the Black patients actually had a higher creatinine for the same GFR as the white patients.
NARRATOR: Researchers assumed the higher creatinine level in the small sample of Black patients was due to their naturally "greater muscle mass."
AMAKA ENEANYA: Where that science comes from really goes back to slavery, right, and how Black bodies were assumed to be different.
Skulls were a different size, bones were thicker.
Amongst Black slaves, lung capacity was different, based on absolutely no science.
Pseudoscience, as they call it.
NARRATOR: Other factors that might increase creatinine, like diet, medications, or dehydration, had not been considered.
ENEANYA: There's been no study to date that has ever proven that Black individuals, just by being Black, have more muscle mass than any other race.
NARRATOR: Nonetheless, a corrective race factor was added to the equation to account for the higher creatinine levels and supposedly greater muscle mass.
Now, instead of showing the true function of their kidneys, the equation calculated that Black patients' kidneys were healthier than they really were.
MUMFORD: I was told that it takes three to four years to, you know, be on the list for three or four years before you're even considered to get a kidney.
I got depressed with that.
HOENIG: It was just shocking how long most of us in the field had accepted the formula without questioning.
♪ ♪ And so after, when I met with students, I said, "You know what?
"We could change this.
Why don't we just change it?"
♪ ♪ So that's what we set out to do.
NARRATOR: 11 months later, in 2017, Beth Israel Deaconess Hospital in Boston became the first medical institution in the country to remove the race variable from the eGFR calculation.
Medical students pressured hospitals across the country to drop eGFR's race factor.
But the majority of hospitals didn't update their eGFR equation, and the algorithm continued to deny many Black patients access to kidney transplants.
I had a family member that was diagnosed with advanced chronic kidney disease.
I was told that he would not be listed for a kidney transplant because his eGFR was too high.
NARRATOR: In 2019, Dr. Amaka Eneanya published a paper on the harmful consequences of using a race-correction factor in the eGFR equation.
ENEANYA: I went to the science.
I picked apart that statistical equation.
I picked apart the performance metrics used to assess equations.
NARRATOR: Her findings added to a growing firestorm.
MAN: The critical race theory has now come to medical school.
♪ ♪ I received the most resistance from my fellow nephrologists, to be honest.
PAVLAKIS: The pushback was, "Just because you don't like it "doesn't mean it's not true.
"It's data-driven, it's research-based.
"It's what we've been doing.
How could it be so wrong?"
♪ ♪ It suggests that what you've been doing for years had a negative impact on Black patients in this country.
♪ ♪ That's a very painful thing for, uh, physicians to contemplate.
PROTESTERS (chanting): No justice, no peace.
On the sidewalks, in the streets.
No justice, no peace.
ENEANYA: Collectively, we became seen as the woke movement, and that we were anti-science.
NARRATOR: But in fact, the problem turned out to be much bigger than the eGFR algorithm.
VYAS: Over time, as we got further along in our clinical training, we realized how many more examples there are of race-based correction or race-based guidelines.
It was everywhere.
♪ ♪ NARRATOR: Guidelines for treating high blood pressure advised different medications for Black patients.
The osteoporosis risk score added five points for non-Black patients, implying Black people were at far lower risk for this disease.
The vaginal birth after cesarean, or VBAC, calculator assumed that Black and Hispanic women were less likely to have a successful vaginal birth after a cesarean section.
In 2020, Dr. Darshali Vyas and colleagues investigated these and other race-based algorithms, along with the original studies they were based on.
A lot of those studies do originate in the antebellum period to validate and to continue the enslavement of Black people at that time.
MORSE: So there were all of these algorithms hidden in plain sight that I used every day as a doctor that unfortunately misused race or used race in a way that essentially normalized or exacerbated racial inequities in health outcomes.
NARRATOR: That year, Dr. Michelle Morse was a health policy fellow for the House Committee on Ways and Means.
When she shared Dr. Vyas's paper with committee members, serious questions followed.
Medical associations across the country were instructed to report to the committee on their use of race-based clinical tools.
♪ ♪ Meanwhile, for Gregory and Pipier, time was running out.
SMITH-MUMFORD: I'm reaching out to family and friends in a letter that I'd written from both of us that says, "Gregory needs a kidney transplant, and we're trying to find someone who'd be willing to be a donor."
NARRATOR: The desperate couple had no idea help was on its way.
PAVLAKIS: So the National Kidney Foundation and the American Society of Nephrology formed a task force and eventually dropped the race variable completely.
But as that was happening, um, I was actually on, the vice chair of the Kidney Transplantation Committee for the Nationwide Organ Procurement Transplant Network.
I proposed that we actually change the wording of national policy that race could not be used in the kidney function estimate for access to the transplant list.
ENEANYA: None of the 240 or so transplant centers could use a race-based eGFR equation-- mandatory.
NARRATOR: And there was more.
The country's transplant programs would now review their kidney transplant lists with a new, race-neutral eGFR algorithm.
The result?
More than 14,000 Black American kidney patients saw their transplant waiting time modified, reflecting the true severity of their kidney disease.
It's time.
I'm in the hospital getting ready for my transplant!
ENEANYA: And to see people tag me in social media, make videos...
The kidney right now is operating well.
ENEANYA: My family member received 18 months back on the waitlist.
That, um, words can't describe.
I mean, it made all of this worth it.
♪ ♪ NARRATOR: Instead of a three- to four-year wait, Gregory Mumford's kidney transplant came after just a few months.
MUMFORD: When they changed it, and they said, "Your name jumped right to the top of the list."
So, a lot of people got kidneys because of that change.
SMITH-MUMFORD: So this is a picture that we laugh about because it's, on the one hand, kind of funny.
On the other hand, it's, like, but it's so serious.
But it's a way to lighten up such a serious thing.
♪ ♪ SIDDIQUE: I truly believe that we genuinely don't know how many race-based algorithms are out there.
Many of the algorithms that are being utilized, unfortunately, are not transparent.
And so, we're unable to vet them.
VYAS: I strongly believe that we should continue to study race and its effects on healthcare and how it affects outcomes of our patients.
MORSE: We need to have standards on how race and ethnicity should be used and should not be used in clinical algorithms.
VYAS: It's not about being woke or not being woke.
It's about making sure that our tools are safe and accurate and do the best job at taking care of our patients.
♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪ ♪
Support for PBS provided by:
Major funding for this program is provided by the Robert Wood Johnson Foundation, the Doris Duke Foundation, the Alfred P. Sloan Foundation, and The California Endowment. Additional funding is provided...