This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

We will undertake an individual patient data (IPD) meta‐analysis of all available trials to study the benefits and possible weaknesses of using PCT cut‐off values in patients with ARTIs as a method of deciding whether to initiate or withhold antibiotic therapy.

Our study hypothesis is that a strategy to initiate or withhold antibiotic therapy in patients with ARTIs based on PCT levels is not inferior in terms of clinical outcomes as compared to routine care or care based on guideline recommendations. Our secondary hypothesis is that patients treated according to a PCT algorithm have less exposure to antibiotics.