Inappropriate antibiotic prescribing for lower respiratory tract infection (LRTI) is widespread and promotes bacterial resistance while increasing costs and incidence of drug-related adverse effects. Researchers evaluated whether use of a serum procalcitonin (PCT)-based algorithm could safely reduce antibiotic administration for LRTI (defined as community-acquired pneumonia, exacerbation of chronic obstructive pulmonary disease, or acute bronchitis). The algorithm encouraged or discouraged antibiotic use according to different PCT cutoff values. Investigators randomized 1359 consecutive adult patients who presented to six tertiary care hospital emergency departments in Switzerland with LRTI diagnosed by clinical and laboratory criteria to r…