Antimicrobial resistance (AMR) represents one of the most urgent public health challenges worldwide, with more than one million resistant infections diagnosed each year. A substantial driver of this problem is antimicrobial use in outpatient settings, where over 200 million antimicrobial prescriptions are written annually across primary care clinics, urgent care centers, emergency departments, and skilled nursing facilities. While antimicrobial stewardship (AMS) programs have traditionally focused on inpatient environments, comparatively little oversight exists in ambulatory care. This gap contributes not only to unnecessary prescribing but also to widening inequities in the diagnosis and management of infections, particularly among marginalized populations.

Marginalization itself is not a biological risk factor for AMR. However, systemic factors such as racism, classism, and inequities in the social determinants of health—including education, socioeconomic status, and access to healthcare—create conditions that increase vulnerability to delayed or inadequate diagnosis and treatment. Communities with fewer healthcare resources may experience shortages of providers, reduced access to diagnostic testing, and lower health literacy, all of which can lead to inappropriate antimicrobial use and higher risk of resistant infections.

Integrating diagnostics with stewardship principles has transformed inpatient AMS efforts, and similar opportunities exist in outpatient care. Rapid diagnostic tests (RDTs) offer timely, actionable information that can differentiate viral from bacterial infections—especially for upper respiratory tract infections, a leading source of unnecessary antibiotic prescribing. When used appropriately, these tools can reduce empiric antibiotic use and improve prescribing confidence.

Rapid antigen diagnostic tests are inexpensive and widely used at the point of care, providing results within minutes for pathogens such as Group A Streptococcus, influenza viruses, and SARS-CoV-2. However, their moderate sensitivity can limit reliability, sometimes prompting confirmatory testing or “just in case” antibiotic prescribing.

Molecular RDTs address many of these limitations by offering substantially higher sensitivity and specificity and, in some cases, the ability to detect multiple viral and bacterial targets simultaneously within 15–90 minutes. Studies demonstrate that multiplex molecular point-of-care testing can reduce antibiotic prescribing, shorten length of stay in emergency departments, and improve patient satisfaction—benefits that are particularly pronounced among racially and ethnically marginalized patients.

Despite their promise, significant barriers remain to equitable deployment of RDTs in outpatient settings. Data from the COVID-19 pandemic revealed that communities with higher social vulnerability often had fewer test-to-treat sites and reduced access to diagnostics. Additional challenges include staffing shortages, training and competency requirements, regulatory compliance, storage and handling specifications, and inconsistent reimbursement. Without deliberate strategies, these obstacles risk exacerbating existing disparities.

Several evidence-based approaches can support equitable integration of diagnostics into outpatient AMS. Low-resource stewardship interventions—such as antibiotic commitment posters, delayed prescribing strategies, and clinical decision support tools—can complement diagnostic testing. Pairing molecular RDTs with clinical prediction rules improves pre-test probability and optimizes use. Surveillance systems that provide near real-time pathogen trend data can further inform local prescribing decisions. Importantly, patient and caregiver education is essential, as public understanding of antibiotic risks and resistance strongly influences prescribing in the community.

Frameworks that prioritize equity, such as the EASE (Equity in Antimicrobial Stewardship Efforts) model, encourage institutions to analyze local data, identify disparities, and design targeted interventions. Focusing RDT deployment on patients at higher risk for resistant infections may ensure timely, appropriate therapy while reducing the spread of resistance.

Advances in diagnostics have made faster, more accurate, and broader pathogen detection possible. When integrated into outpatient stewardship programs with an equity lens, RDTs can strengthen antibiotic prescribing practices, reduce unnecessary antimicrobial use, and help close longstanding gaps in AMR-related health outcomes, benefiting both individual patients and public health.

Affiliations

1. Department of Pathology, Wake Forest University School of Medicine, Winston Salem, NC, USA.
2. Divisions of Clinical Pharmacy and Black Diaspora and African American Studies, Skaggs School of Pharmacy, University of California San Diego, La Jolla, California, USA.
3. bioMérieux, Medical Affairs, Salt Lake City, UT, USA