Using a fast, point-of-care test (POCT) for bacterial infection may help reduce excessive use of antibiotics, suggests a systemic review published in The Cochrane Library. Antibiotics are widely prescribed, often for acute respiratory infections caused by viruses that do not respond to these medications, because doctors do not have an immediate way of knowing if patients’ illnesses are bacterial or viral.

However, as common antibiotics become less effective in treating serious bacterial infections due to bacterial resistance, researchers have been looking at ways to better identify bacterial illnesses earlier. In this review, the researchers examined evidence from randomized trials that use a C-reactive protein test, which is the only POCT kit currently available to general practitioners and meant to help guide them on when to prescribe antibiotics. “It involves testing a single drop of blood collected by pricking the patient's finger and takes about three minutes,” according to a press release. “C-reactive protein acts as a so-called ‘biomarker’ of inflammation and low levels may effectively rule out serious bacterial infection, meaning that use of antibiotics would be unnecessary.”

The researchers looked at data from six trials that included 3,284 mostly adult patients. Of those, 631 of 1,685 people who took the test were prescribed antibiotics, compared with 785 of 1,599 patients who didn’t take the test.

The use of antibiotics was 22% lower in the group who underwent POCT. “However, the results varied considerably between studies, possibly due to differences in the way they were designed,” according to the press release. “This makes interpretation of the findings more difficult.” There was also no difference between the groups in how long patients took to recover from their illnesses.

“These results suggest that antibiotic use in patients with acute respiratory infections could be reduced by carrying out biomarker tests, in addition to routine examinations,” said lead researcher Rune Aabenhus, of the Department of Public Health at the University of Copenhagen in Copenhagen, Denmark, in a prepared statement. “Going forward, it would be useful to see more evidence on the size of the reduction and cost-savings, as well as how these tests compare to other antibiotic-saving approaches.”

The analysis found that the test was safe overall, but one of the six trials—involving a small number of cases—found that those who took the test were more likely to eventually be admitted to the hospital. “This result may have been a chance finding, but it does remind us that general practitioners need to be careful about how they use these tests,” Aabenhus explained.