The use of a quick blood test for CRP levels to determine whether an infection required treatment led to a 30% fall in prescriptions of antibiotics, their study found.
The researchers hope the finding will encourage use of the test in primary care to distinguish between self-limiting viral infections that do not require antibiotics, and potentially fatal LRTIs such as bacterial pneumonia.
The study was published in the journal BMC Family Practice. It tracked 179 patients presenting with acute cough or respiratory tract infection, of which 101 were tested for CRP using a simple blood test that returns a result within five minutes. The remainder acted as a control group.
CRP levels in the blood rise in response to infection and tissue damage. High levels are known to be correlated with the presence of pneumonia, whereas levels below 20mg/L usually do not require antibiotics.
Researchers found the rate of antibiotic prescribing was lower when CRP testing was used to steer treatment, at 37.6% compared with 58.9% in the control group. Referral for chest X-ray was also lower among patients tested for CRP levels.
Recovery rates were similar between groups, at 92.9% and 93.6% in the testing and control groups respectively.
Helps GPs fight drug resistance
Study authors said: ‘Careful use and interpretation of CRP testing in patients with respiratory tract infections has the potential to benefit patients and to help GPs in the important struggle against antibiotic resistance.’
Reducing the number of antibiotics prescribed has been recommended by numerous health organisations including the WHO and the NHS, and follows an increase in the number of antibiotic-resistant strains of bacteria over the last 20 years.
In most cases, the CRP test helps to reduce diagnostic uncertainty, but it cannot fully differentiate between bacterial and viral infections.
However, the use of CRP testing in primary care has been recommended in the latest European guidelines for treatment of LRTIs and is routinely used in Nordic countries for both upper and lower respiratory tract infections.