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Incorporating socioeconomic indices into clinical decisions may refine antibiotic treatments, potentially curbing antimicrobial resistance.

Communities with a high level of socioeconomic deprivation are more likely to have higher rates of antimicrobial-resistant organisms compared with other neighborhoods, according to findings recently published in Clinical Infectious Diseases.

“Many chronic health issues, such as diabetes, high blood pressure, and high cholesterol, have been found to be exacerbated by socioeconomic-based health inequities. In the field of infectious diseases, only recently, the COVID-19 pandemic helped to make many aware of the consequences of socioeconomic inequities,” Lauren Cooper, MS, told Physician’s Weekly. “Additionally, there is not a large amount of research that has been completed on socioeconomic inequities and antimicrobial resistance. Therefore, our research is relatively novel.”

Tracking Antimicrobial Resistance in the Community

Cooper and colleagues used electronic health records of positive bacterial cultures collected from patients at two large hospital systems in the Dallas-Fort Worth metropolitan area to identify antimicrobial resistance patterns. The investigators noted patients’ primary home addresses and geocoded the cultures to specific areas based on census information.

“We were able to determine ‘hotspot’ areas where antimicrobial resistance prevalence was at higher levels than surrounding areas,” Cooper explains. “We conducted geospatial analysis such as bivariate Moran’s I tests to determine the relationship between antimicrobial resistance prevalence and socioeconomic indices such as the Area Deprivation Index and the Social Vulnerability Index.”

The bacterial cultures were all taken between 2015 and 2020. Cooper and colleagues standardized the case counts per 1,000 persons per area population for each organism included in the study. They used spatial autocorrelation tests to identify geographic areas with high and low prevalence of antimicrobial-resistant organisms and linked this information with established socioeconomic data. Researchers chose five different organisms to represent antimicrobial resistance: MRSA, vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Enterobacterales (CRE), extended spectrum beta-lactamase producers (ESBL), and AmpC beta-lactamase producers. They also used the Social Vulnerability Index and the Area Deprivation Index to determine an area’s socioeconomic status.

A Deeper Look at the Data

Cooper and colleagues included 43,677 cultures from 32,897 patients. Patients were mostly White (76.7%) and non-Hispanic (78.6%). Most were women (59.9%), and 38% were aged between 65 and 84 years.

The researchers reported that MRSA was the most common organism of interest, appearing in 19,019 (43.5%) cultures. The second most commonly recorded was ESBL-producing organisms, occurring in 13,555 (31%) of cultures, followed by CRE (11.3%), VRE (8.2%), and AmpC (5.9%).

“In our study, we found that not only were there geographic areas in which there were higher levels of antimicrobial resistance compared to surrounding areas, there was also co-location and spatial correlation between the prevalence of antimicrobial resistance and the Area Deprivation Index,” Cooper explained. “In the Dallas-Fort Worth metropolitan area, there is a significant geospatial association between a well-known socioeconomic disparity index (Area Deprivation Index) and the prevalence of antimicrobial resistance, particularly among Amp C beta-lactamase Gram negatives and MRSA.”

Although there was no significant association between any given organism and the Social Vulnerability Index, the researchers wrote there was “a significant spatial relation” between each of the five organisms studied and a location’s Area Deprivation Index.

Considering Geographic Location in the Clinic

“The addition of socioeconomic indices, like the area deprivation index, in clinical decision-making could help with determining more precise empiric antibiotic treatments for patients and a possible reduction in overly broad antibiotics that could exacerbate antimicrobial resistance in the future,” Cooper said. “A further look into relationships between the individual components of the Area Deprivation Index and antimicrobial resistance will expand this research and give a better viewpoint into possibly why [relationships between] antimicrobial resistance and socioeconomic inequities exist.”

Researchers cautioned, however, that the data represents only the Dallas-Fort Worth area. More work will be necessary to see if these disparities exist in other major cities.

“We have yet to see if it could be applied to broader geographic areas but are hopeful that this will be the case,” Cooper said.