NEW YORK – A study published Tuesday in JAMA Network Open found that Black patients discharged from the emergency department are significantly less likely than White patients to receive related diagnostic testing.
The study, conducted by researchers from Johns Hopkins University, looked at emergency department discharges, hospital observation stays, and hospital admissions via administrative claims from EDs and acute care hospitals in Kentucky, Maryland, North Carolina, and New Jersey from 2016 to 2018. Using a previously validated diagnostic intensity index, the researchers evaluated differences in diagnostic testing rates by race and ethnicity. Diagnostic intensity describes rates of diagnostic test use and the index uses the yield of information from testing to infer potential test overuse, the researchers wrote.
The index, according to the paper, pairs nonspecific principal discharge diagnoses like nausea and vomiting, abdominal pain, chest pain, and syncope with related diagnostic tests to estimate rates of nondiagnostic testing. The researchers calculated the adjusted odds ratio of receiving a test related to the principal discharge diagnosis by race and ethnicity and controlled for the patient's primary payor and zip code income quartile.
Of the nearly 3.7 million encounters analyzed, most were ED discharges. Black patients discharged from the ED with a diagnosis of interest had an adjusted odds ratio of 0.74 of having related diagnostic testing, the researchers noted. No other racial or ethnic disparities of a similar magnitude were observed in any acute care settings.
White patients discharged from the ED had higher rates of testing paired with nonspecific principal diagnoses, and therefore had higher rates of nondiagnostic testing for conditions of interest.
"This suggests that White patients may receive more test overuse but also raises the concern that undertesting among Black patients may lead to more missed diagnoses," the researchers wrote.
They noted that the drivers of the disparities were unclear but that there is "strong evidence of racial bias in the ED triage process." Triage disparities could bias the clinician who cares for the patient after triage but "could also impact where the patient is placed in the ED, tests ordered, and type of clinician a patient sees," they added.
One other possible explanation is that communication difficulty between physicians who are predominantly White and Black patients leads to those patients' symptoms being dismissed more often, the researchers wrote.
Because the researchers did not study test underuse, they said their ability to evaluate variation in missed diagnoses across races and ethnicities was limited. "Without longitudinal data, we were unable to determine whether our findings showing less test overuse for patients discharged from the ED were accompanied by test underuse and more missed diagnoses," they added.
The research team was also unable to fully adjust for patient education and income level, which could affect testing, and lacked data on ED triage.