Reference	Objective	Design	Evidence
Van de Meer et al. [229]	To evaluate the diagnostic accuracy of C‐reactive protein in detecting radiologically proved pneumonia and to evaluate how well it can discriminate between bacterial and viral infections of the lower respiratory tract	MA	1A+
Graffelman et al. [94]	To evaluate the diagnostic value of medical history, physical examinations and additional tests in discriminating between viral and bacterial infections in patients with acute cough	PCS	3B+
Holm et al. [228]	To evaluate the diagnostic value of CRP and PCT in discriminating between bacterial and viral lower respiratory tract infections	PCS	3A+