Providing procalcitonin levels does not reduce antibiotic use in patients with lower respiratory tract infections

Reference

Huang DT, Yealy DM, Filbin MR, et al, for the ProACT Investigators. Procalcitonin-guided use of antibiotics for lower respiratory tract infections. N Engl J Med 2018;379(3):236-249.

Synopsis

This multicenter trial conducted in the United States included adults with LRTIs for whom the emergency department physician was uncertain whether antibiotic therapy was indicated. investigators randomized the 1664 patients into either a usual care group or a procalcitonin group, in which clinicians were provided with patients' procalcitonin levels and had access to a procalcitonin-based antibiotic prescribing guideline. This guideline states that antibiotics are strongly discouraged for procalcitonin levels of less than 0.1ug/L, discouraged for 0.1 to 0.25 ug/L, recommended for levels of 0.25 to 0.5 ug/L, and strongly recommended for levels greater than 0.5 ug/L. Procalcitonin levels were drawn in the emergency department and, if a patient was hospitalized, they were drawn serially throughout the hospital stay. Final diagnoses for study patients included acute asthma exacerbation (39.3%), acute chronic obstructive pulmonary disease exacerbation (31.9%), acute bronchitis (24.2%), and community-acquired pneumonia (19.9%). The initial procalcitonin level was less than 0.1 ug/L in almost 80% of the patients. Despite this, approximately 60% of patients in both groups were exposed to antibiotics at some point during the 30-day period. Overall, no statistically significant difference was detected between the 2 groups in antibiotic exposure and adverse outcomes. In cases of low procalcitonin where antibiotics were still prescribed, the most common reasons were clinician belief that the patient had a bacterial infection or that the patient had an acute chronic obstructive pulmonary disease exacerbation that required antibiotics.