Rapid Tests Alone Don’t Curb Antibiotic Use for Respiratory Infections, Study Finds

New research suggests that simply providing rapid diagnostic tests in primary care settings isn’t enough to significantly reduce antibiotic prescriptions for common respiratory infections. A large international trial, involving nearly 2,700 patients across 13 European countries, found no statistically significant difference in antibiotic prescribing rates between those who received point-of-care testing and those who received usual care. The findings, published in The Lancet Primary Care, underscore the complexity of antibiotic stewardship and highlight the demand for more comprehensive strategies.

Understanding the PRUDENCE Trial and its Findings

The study, known as the PRUDENCE trial, enrolled patients aged one year and older presenting with cough or sore throat, where their clinician was already considering prescribing antibiotics. Participants were randomly assigned to either standard care or standard care plus a point-of-care testing strategy. These tests included measures of inflammation (CRP), rapid strep tests for throat infections, and tests for influenza A and B, chosen based on symptoms and the time of year. The full study details are available in The Lancet Primary Care.

Antibiotics were prescribed to 45.7% of patients in the testing group, compared to 47.1% in the usual care group – a difference that researchers determined wasn’t statistically meaningful. Importantly, recovery rates were similar in both groups, with patients taking an average of four days to return to their normal activities. There was similarly no indication that the testing strategy led to more complications or adverse events.

Approximately 90% of all antibiotics are prescribed by general practitioners in primary care, with the vast majority being for respiratory infections. Many of these infections are viral and don’t respond to antibiotics, contributing to the growing problem of antibiotic resistance. Point-of-care tests have been promoted as a way to help clinicians differentiate between bacterial and viral infections, reducing unnecessary prescriptions.

Why Testing Alone Isn’t the Answer: A Qualitative Perspective

Alongside the clinical trial, researchers conducted a qualitative study, interviewing 56 patients and 33 clinicians across six countries. This study aimed to understand how point-of-care tests were actually used in practice and why the trial didn’t result in a substantial reduction in antibiotic prescribing. The findings, published alongside the trial results, revealed that clinicians often used test results to confirm existing decisions rather than change them.

When a clinician strongly suspected a bacterial infection, they frequently prioritized their clinical judgment over test results, sometimes even questioning the accuracy of the test itself. Tests were most influential when there was genuine diagnostic uncertainty – when symptoms were vague or it was difficult to determine whether an infection was bacterial or viral. However, even in these cases, factors like patient expectations, the perceived severity of the illness, and cultural norms surrounding antibiotic use often outweighed test results.

Professor Sarah Tonkin-Crine, a senior co-author of the qualitative study from the Nuffield Department of Primary Care Health Sciences at the University of Oxford, explained, “The results of our study suggest that diagnostic tests alone are not sufficient. Clinicians across six highly different countries and health systems described the same patterns; the primacy of clinical intuition, the pressure of perceived patient expectations and the difficulty of acting on a test result that conflicts with your own assessment. These are fundamental to making clinical decisions.”

The Role of Clinical Intuition and Patient Expectations

The study highlights the powerful influence of clinical experience and intuition in medical decision-making. While diagnostic tests can provide valuable information, they are often interpreted within the context of a clinician’s overall assessment of the patient. Patient expectations also play a significant role. In many cultures, there’s a strong belief that antibiotics are necessary for any infection, and patients may pressure their doctors to prescribe them even when they aren’t needed. Research into social norms and antibiotic prescribing suggests these pressures are deeply ingrained.

Professor Chris Butler, lead author of the trial from the University of Oxford, emphasized that point-of-care tests have potential, but they aren’t a magic bullet. “Our study shows that diagnostics on their own do not inevitably change prescribing decisions. When clinicians are already leaning towards antibiotics, test results often reinforce that choice. To make a meaningful difference, rapid testing must be combined with clear guidance, clinician training, and support to manage patient expectations.”

What Does This Indicate for Antibiotic Stewardship?

These findings have important implications for antibiotic stewardship programs, which aim to reduce inappropriate antibiotic use and combat antibiotic resistance. The research suggests that simply providing diagnostic tests isn’t enough. A more comprehensive approach is needed, one that addresses the complex interplay of clinical judgment, patient expectations, and cultural norms.

This includes providing clinicians with clear guidelines on when to use tests and how to interpret the results, as well as training on effective communication strategies to manage patient expectations. It also requires addressing the underlying beliefs and attitudes that drive unnecessary antibiotic prescribing. The University of Oxford is actively involved in researching these complex issues.

Looking Ahead: Integrating Diagnostics into Broader Strategies

The question now isn’t whether point-of-care tests work in primary care, but under what conditions they can be most effective. Future research should focus on identifying the specific strategies and interventions that can maximize the impact of diagnostic testing. This includes exploring ways to address cognitive dissonance – the discomfort that arises when test results challenge a clinician’s initial assessment – and providing clinicians with the support they need to confidently act on test results, even when they conflict with their own intuition.

Diagnostic testing remains a key component of national and international action plans to reduce inappropriate antibiotic use. However, these studies demonstrate that tests alone are insufficient. They must be integrated into broader, multifaceted strategies that include structured clinician training, clear guidance on the safety of following test results, and efforts to address the social and cultural factors that contribute to antibiotic overuse.

Further research is needed to determine the optimal ways to implement and evaluate these strategies, ultimately aiming to preserve the effectiveness of antibiotics for future generations.