Reliability of Admission Procalcitonin Testing for Capturing Bacteremia Across the Sepsis Spectrum: Real-World Utilization and Performance Characteristics, 65 U.S. Hospitals, 2008–2017
Procalcitonin-on-admission testing for patients with suspected bloodstream infections (BSIs) is often conducted, but its performance remains disputed. 📊 This research paper represents the largest study to date on the use of procalcitonin for identifying patients with bloodstream infections (BSI) in U.S. hospitals. Here are the key points:
🩺The study was a retrospective cohort study utilizing the Cerner HealthFacts Database from 2008 to 2017, and included all adult inpatients (≥ 18 years) who had blood cultures and procalcitonin tests within 24 hours of admission.
⚕️The study assessed the testing frequency of procalcitonin, sensitivity for detecting BSIs caused by different pathogens, and the discriminatory ability of procalcitonin-on-admission for BSI in patients with or without fever/hypothermia, ICU admission, and sepsis.
Out of 739,130 patients in 65 hospitals, 10.1% had admission blood cultures and procalcitonin tests. Most patients (83%) did not have repeat procalcitonin tests on admission day.
🩸 The sensitivity of procalcitonin at a commonly used cutoff of 0.5 ng/mL for detecting BSI upon hospital admission was found to be low at 68%, making it a weak rule-out test for BSI.
📉 Lowering the cutoff for procalcitonin positivity increased sensitivity (e.g., 87.8% at ≥ 0.1 ng/mL) but significantly reduced specificity (e.g., 32.7% at ≥ 0.1 ng/mL vs. 65.6% at ≥ 0.5 ng/mL).
🔍The negative predictive value (NPV) of procalcitonin was excellent, but the prevalence of BSI and prior antibiotic use could impact its interpretation.
📈 Procalcitonin showed moderate discrimination for overall BSI (AUC, 0.73), but its performance did not significantly improve based on the presence of fever, sepsis, or shock.
💊 Procalcitonin results did not significantly affect the initiation of empiric antibiotic treatment in patients with suspected BSI.
🔄 Trends in procalcitonin levels could have prognostic utility, but the test was often not repeated after admission, potentially leading to missed opportunities for antibiotic discontinuation.
🦠 Procalcitonin values varied considerably based on the pathogens isolated from blood, potentially impacting treatment decisions.
📝 In summary, the study found that procalcitonin-on-admission had poor sensitivity for ruling out BSI, moderate-to-poor discrimination for bacteremic sepsis and BSI, and did not substantially impact empiric antibiotic usage. The paper suggests the need for diagnostic stewardship and risk assessment when using admission procalcitonin-guided clinical decisions.