A retrospective cohort study from the Duke University Health System scrutinized inpatient Clostridioides difficile infection (CDI) testing at three hospitals, focusing on racial disparities in the administration of tests. The outcome depicted a higher rate of testing among White patients compared to Black or non-White non-Black (NWNB) patients, suggesting a potential racial inequity in testing. The study provided further evidence for the findings of previous studies that showed White individuals received CDI tests more frequent while being at a higher exposure risk for the C. difficile bacteria.
Clostridioides difficile is a bacteria that causes approximately half a million infections in the US annually, according to approximations from the US Centers for Disease Control and Prevention. Factors increasing the vulnerability to this infection include age (being 65 or older), weak immune system, recent stay at a hospital or nursing home, and previous infection or known exposure to Clostridioides difficile. Testing is crucial to identify and contain CDI, particularly in inpatient settings. However, racial discrepancies in testing and positivity rates may have significant implications.
Led by Bobby Warren, MPS, lab director of the Disinfection, Resistance and Transmission Epidemiology Lab at Duke Antimicrobial Stewardship Outreach Network, this investigation endeavors to build on existing research about racial disparities in CDI testing. It examines race-specific patient days to control for disproportionate time spent in hospital between races and uses electronic health record data to make its assessment.
Disallowing participation of patients who either declined to answer the race question or did not have their race listed, the study categorized self-reported race data into three groups: White, Black, and NWNB. The investigation focused on inpatient encounters from three hospitals over a seven-year period, analyzing proportions of positive tests according to race, year, and hospital. An inpatient encounter was characterized as a unique interaction involving exposure to an inpatient unit for at least one full day.
The study ascertained primary outcomes by the number of CDI tests conducted per 1,000 race-specific patient days, with the secondary outcome as the percent positivity by race. Among the three hospitals, which collectively conducted over 35,000 CDI tests over approximately 2.5 million patient days, White patients received the most testing (21,695 tests), followed by Black (11,846) and NWNB patients (1,619). From these tests, 15% were positive, with White patients accounting for 62% of positive tests, Black 35%, and NWNB patients 4%. When taking into account patient days by race, White patients still received more CDI tests than the other two racial categories.
Despite similar rates of test positivity among racial groups, the observed lower CDI testing rate for Black patients could suggest an occurrence of racial inequity in testing. The study concluded with the recommendation for further research to understand the cause of this disparity and whether geographical factors or differences in access to care or in selection for testing had an impact.