Lead
Current tests do not allow GPs to determine with sufficient accuracy whether a patient has pneumonia requiring antibiotic therapy. We are increasing the precision of diagnosis by combining two new diagnostic tests with an algorithm.

Lay summary

General practitioners too often prescribe antibiotics for acute respiratory tract infections because they cannot distinguish between bacterial pneumonia and non-bacterial infections. In order to improve diagnosis we are developing a procedure that combines ultrasound examination of the lungs with a procalcitonin test helping in differentiating between bacterial and viral infections. However, since each method on its own produces too many unreliable diagnoses, we are combining their results with an algorithm to increase diagnostic precision. In our study, several general practitioners are using this strategy, and we are comparing the amount of antibiotics they prescribe and the therapeutic outcomes with those of a comparator group who are not using the strategy.

Background
Acute respiratory tract infections are among the most frequent reasons for unnecessary prescription of antibiotics. Use of these medicines for these infections needs to be reduced.

Aim
Our aim is to develop a low-cost, practicable method capable of determining with greater precision than in the past which patients with respiratory tract infections have pneumonia that requires treatment with antibiotics.

Relevance
Since our method requires only a small mobile ultrasound and a rapid, easy-to-perform test, it is suitable for a wide variety of settings and could be widely deployed very rapidly. We are also asking the doctors taking part in our study about criteria which tend to favour or hinder the use of the method.