Usefulness of procalcitonin measurement in reducing antibiotic use and identifying serious bacterial illness.

Volume 84, Number 2 www.aafp.org/afp American Family Physician 177 Procalcitonin is a precursor to calcitonin that is elevated only in the presence of a bacterial infection. Measurement of procalcitonin is being pushed as a way to determine the presence or absence of bacterial infection and, therefore, as a way to reduce antibiotic use. But, how well does it work in the patients family physicians see? Why are the results of this study not as convincingly positive as the results of other studies?