Testing for C-reactive protein can reduce unnecessary antibiotic use in patients experiencing an exacerbation of chronic obstructive pulmonary disease without causing patient harm, a UK study shows.

In the study, known as PACE, 653 patients attending 86 UK GP practices for an acute exacerbation of COPD were randomly assigned to either usual care, or a decision on whether or not to prescribe antibiotics on the basis of a C-reactive protein (CRP) test.

Patient-reported use of antibiotics in the CRP arm was 57% compared with 77% in the usual care arm, a difference of 20 percentage points, the researchers reported in the New England Journal of Medicine.

Meanwhile, clinical outcomes at two weeks as reported on the Clinical COPD Questionnaire were -0.19 points in favour of the CRP group.