Procalcitonin Antibiotic Consensus Trial (ProACT)

There is a need for improved decision-making for antibiotic prescription in acute suspected
infection. Infections, particularly in the early stages, can have protean manifestations,
often do not manifest with "classic" signs, and clinically overlap with non-infectious
conditions. However, the imperative to quickly give antibiotics for bacterial infection has
led to antibiotic overuse and resistance.

Strategies that combine novel diagnostics with therapeutics have improved decision-making in
oncology, cardiology, and other fields. These strategies aim to identify those patients most
likely to be helped or harmed by the therapeutic intervention and allow more individualized
care. This approach takes diagnostics to the next level, by demanding a test not only measure
well, but also that clinical care be improved by tying the test to a treatment strategy.

Procalcitonin, a novel biomarker of bacterial infection, may help physicians make more
appropriate antibiotic decisions. Lower respiratory tract infection (LRTI) is an ideal trial
population. LRTI accounts for a large proportion of antibiotic prescription, and exemplifies
the imprecise clinical phenotype of infection.However, key questions of generalizability and
safety preclude widespread application.

Inclusion Criteria:

- ≥ 18 years old

- A primary clinical diagnosis in the ED of acute LRTI (< 28 days duration)

- Clinician willing to consider procalcitonin in antibiotic decision-making

Exclusion Criteria:

- Systemic antibiotics before ED presentation (All prophylactic antibiotic regimens, OR
received >1 dose within 72 hours prior to ED presentation)

- Current vasopressor use

- Mechanical ventilation (via endotracheal tube)

- Known severe immunosuppression

- Accompanying non-respiratory infections

- Known lung abscess or empyema

- Chronic dialysis

- Metastatic cancer

- Surgery in the past 7 days (excluding minor surgery such as skin biopsy)

- Incarcerated or homeless

- Enrolled in ProACT in the past 30 days