Hospitals are more likely to give drug tests to Black women delivering babies than white women, regardless of the mother’s history of substance use, suggests a new study of a health system in Pennsylvania.
And such excessive testing was unwarranted, the study found: Black women were less likely than white women to test positive for drugs.
The study analyzed the electronic medical records of 37,860 patients who delivered a baby at a large health care system in Pennsylvania between March 2018 and June 2021. It was published on Friday in the journal JAMA Health Forum.
The report comes amid a national conversation about health disparities and systemic racism in medicine, one that was triggered by the Covid-19 pandemic’s disproportionate toll on communities of color, and that has focused more recently on high maternal mortality rates among Black and Native American women.
The authors of the new study urged hospitals to examine their drug testing practices in order to address racial biases.
“Any given clinician may not be thinking about bias, but when you look at these kinds of data, you can see there is no other explanation,” said Marian Jarlenski, an associate professor of health policy and management at the University of Pittsburgh School of Public Health and the paper’s first author.
The findings are a “clear illustration of disparate care,” said Dr. Alison Stuebe, a professor of obstetrics and gynecology at the University of North Carolina, who was not involved in the research. “This study is one example of how provider behavior causes Black women to distrust the health care system.”
After controlling for various demographic and medical factors, the researchers calculated the probability of urine toxicology testing for different groups. Although more Black women had reported prior drug use, mostly of cannabis, the difference did not fully explain the results: Black patients had the highest probability of undergoing urine tests at delivery, regardless of their prior drug use.
Among those who did report substance use in the previous year, the likelihood of being tested was 76 percent for Black women, compared with 68 percent for white women.
Yet white women with a history of substance use were more likely to test positive: About 66.7 percent were likely to test positive, compared with 58 percent of Black patients with such histories.
Even among women who had no history of drug use, Black women were more likely to be tested: About 7 percent of Black patients with no history of substance use were likely to be tested, compared with 4.7 percent of white patients with no history, the study estimated.
Hospitals screen for drug use on labor and delivery wards in order to comply with federal and state regulations for safe care for infants affected by substance use during pregnancy.
It’s not clear what led to greater drug testing of Black women at the Pennsylvania health system. All patients entering the labor and delivery department were screened verbally for substance use, with questions adapted from the National Institute on Drug Abuse’s quick verbal screening test. The policy called for running urine toxicology tests on patients with a positive result from the screening test, a history of substance use in the year before delivery, few prenatal visits or a poor birth outcome without a clear medical explanation.
But substance use history couldn’t fully explain the results. And the researchers found no racial differences in the number of prenatal care visits or the rate of stillbirths.
In addition to calculating probabilities, the study reported the raw number of patients who were tested for drugs. While about 21 percent of Black patients had reported a history of drug or alcohol use, 25 percent underwent urine testing. Most of the Black women had reported cannabis use.
In contrast, 9 percent of white women had reported a history of drug use, including cannabis and opioids, while 10 percent were tested for drugs.
Of the Black mothers tested, 40 percent had positive urine toxicology tests, compared with 51 percent of the white mothers.