Researchers analyzed data from previous studies to see how accurate a blood test for a protein called procalcitonin (PCT) is at diagnosing sepsis. Sepsis is a life-threatening response to infection. The analysis combined results from studies involving 1,098 critically ill adults in intensive care units who were suspected of having an infection. Of these patients, 635 were diagnosed with sepsis and 89 with septic shock.
The main finding was that the PCT test had moderate accuracy. It correctly identified patients with sepsis about 72% of the time (sensitivity). It correctly identified patients without sepsis about 65% of the time (specificity). The overall diagnostic performance, measured by a statistical curve, was 0.79 on a scale where 1.0 is perfect. The review did not report on any safety concerns related to the blood test itself.
The main reason to be careful is that the certainty of this evidence is rated as low. This means the true accuracy of the test might be different. The authors of the review concluded that clinicians should be cautious about using PCT to help diagnose sepsis. For patients and families, this means the PCT test is a tool doctors might use, but it is not definitive. A diagnosis of sepsis still relies heavily on a doctor's overall assessment, other tests, and close monitoring of the patient's condition.
