The utility of procalcitonin as a biomarker of hospital-acquired infection in severe COVID-19

Abstract

<b>What the study adds.</b> During an episode of hospital-acquired infection (HAI) in patients with severe COVID-19, procalcitonin (PCT) levels >1.00 μg/L had a moderate positive predictive value (PPV) of 52%, whereas levels <0.26 μg/L had a negative predictive value (NPV) of 92% for proven HAI. For PCT levels >40 μg/L, the PPV was 100%.<b>Implications of the findings.</b> At levels <0.26 μg/L, PCT had an NPV >90%. This 'rule-out' characteristic of PCT may be especially valuable in scenarios of diagnostic equipoise with regard to the presence of bacterial co-infection. Clinicians should take care to not unjustifiably associate elevations in PCT levels with the presence of bacterial co-infection, unless levels are extremely high, in which case the PPV rises significantly.