The RAPID-TEST study, funded by a partnership between the UKRI Medical Research Council (MRC) and the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation Programme (EME), is the first randomised clinical trial of a rapid multiplex microbiological point-of-care test in primary care. The findings are published in JAMA Internal Medicine today [18 May].
Rapid microbiological point-of-care tests can detect the viruses and less common (atypical) bacteria thought to cause respiratory infections like coughs, colds, sore throats and ear pain. These tests can provide results within minutes, allowing faster diagnoses compared to traditional lab-based methods.
Antibiotics are only effective for treating infections caused by bacteria, not viruses. It is therefore widely thought that use of these tests in primary care could reduce inappropriate antibiotic prescribing and, potentially, the development of antimicrobial resistance.
The surprising finding was due to an increase in antibiotic prescribing when no virus or atypical bacteria were detected, which completely offset a substantial reduction in prescribing for the patients who tested positive for a virus. The study also found that use of the tests made no difference to patient outcomes.
A total of 552 patients recruited from 16 general practices in the southwest of England took part in the study, half receiving the test and the other half receiving usual care.
There was no difference in antibiotic prescribing rates between the two groups, with same-day antibiotics prescribed to 45% of patients in both groups. Two-thirds of the prescriptions were for immediate use and one-third were for delayed use (to be collected from the pharmacy later as advised by the clinician).
Although antibiotic prescribing was halved in the 40% of patients who tested positive for a virus, this reduction was offset by an increase in antibiotic prescribing when no virus or atypical bacteria were detected.
Patient outcomes were similar across the two groups. All patients who took part in the study were asked to report on the presence and severity of key symptoms from 0 ('normal') to six ('as bad as it could be'), until either all symptoms resolved, or 28 days had passed. There were no significant differences between the groups in terms of day 2 to 4 symptom severity or symptom duration.
Other findings included:
- There was no evidence of a change in day 2 to 4 symptom severity in patients who tested positive for a virus compared to those when no virus or atypical bacteria were detected.
- There was no evidence of a difference in the proportion of patients experiencing a 'second sickening' (when patients initially feel better but then later worsen).
- Antibiotic prescribing between days 2 and 28 was similar between the two groups.
- There was no difference in patient-reported antibiotic consumption from days 1 to 28.
- There was no evidence that use of the test led to an increase in healthcare seeking.
Alastair Hay, Professor of Primary Care from the Centre for Academic Primary Care at the University of Bristol, who led the study, said: "To our knowledge, this is the first study to investigate whether a rapid multiplex microbiological point-of-care test reduces antibiotic prescribing in patients with respiratory infections in primary care. We found they did not change either the overall antibiotic prescribing rates, nor the duration and severity of patients' symptoms.
"We conclude that, in their current form, these tests should not be routinely used in primary care. However, future studies could establish the patients and infections in which they are clinically- and cost-effective and investigate whether further information and training could help clinicians use the test results to reduce prescribing safely."
Professor John Simpson, Director of the MRC/NIHR EME Programme, added: "Ensuring we make best use of antibiotics is crucial in tackling and preventing the global threat of antimicrobial resistance. This important study is one of the first of its kind evaluating if a rapid microbiological point-of-care test can help GPs conserve antibiotics.
"However, the findings questioning the usefulness of these tests in primary care demonstrate that complex factors affect GPs' decisions. Further research is urgently needed to determine how best to reduce unnecessary antibiotic prescribing in a way that remains safe for patients."
Paper
'Rapid respiratory microbiological point-of-care-testing to improve antibiotic use in primary care: A randomized clinical trial' by Alastair Hay et al. in JAMA Internal Medicine [open access].
