MISINTERPRETATION of microbiological test results is a frequent yet overlooked driver of inappropriate antibiotic prescriptions, according to new research highlighting the critical role of diagnostic stewardship in antimicrobial management.
While microbiology data are essential for guiding targeted therapy, the review notes that results are often applied incorrectly in clinical decision-making. Common issues include overinterpreting positive cultures from poorly collected or clinically unnecessary samples, mistaking colonization for active infection, and relying too heavily on laboratory results without supporting clinical evidence. These errors can lead to unnecessary antibiotic use, contributing to antimicrobial resistance and exposing patients to avoidable side effects.
The review emphasizes that the problem spans multiple specimen types, including urine, wound, and respiratory samples, as well as laboratory confirmation of Clostridioides difficile infection. In these cases, diagnostic errors often stem from tests ordered without clear clinical indication, as well as uncritical acceptance of culture results.
Promising solutions are emerging through diagnostic stewardship initiatives, which aim to align microbiology practices with appropriate clinical use. Examples include restricting processing of low-yield samples, modifying laboratory reporting to avoid triggering overtreatment, and implementing decision support tools. Interventions such as the BLADDER score for urinary testing and selective result reporting have demonstrated reductions in unnecessary antibiotic use without compromising patient safety.
Successful implementation of these measures depends on close collaboration between microbiology laboratories, clinicians, and antimicrobial stewardship teams. The review concludes that laboratories are not passive data providers but active partners in preventing diagnostic and therapeutic errors. Embedding diagnostic stewardship into daily practice, supported by clinician education, tailored protocols, and ongoing outcome monitoring, can help ensure test results are interpreted in the right clinical context, ultimately safeguarding both antibiotic effectiveness and patient outcomes.
