The diagnostic accuracy of procalcitonin for community-acquired bacteraemia: an updated systematic review and meta-analysis

BACKGROUND: Procalcitonin is known to have moderate diagnostic accuracy for bacteraemia. A 2014 meta-analysis showed 76% sensitivity for a 0.50-ng/mL threshold. Lower thresholds might improve sensitivity. OBJECTIVES: To determine the diagnostic accuracy of procalcitonin for community-acquired bacteraemia by conducting a systematic review and meta-analysis, focusing on the ability to exclude bacteraemia. METHODS: Data sources: We searched PUBMED, EMBASE and Web of Science from 1 January 2014 to 20 May 2025. STUDY ELIGIBILITY CRITERIA AND PARTICIPANTS: Articles studying diagnostic accuracy of procalcitonin for community-acquired bacteraemia in adults. TEST AND REFERENCE STANDARD: Procalcitonin was compared with blood culture results. ASSESSMENT OF RISK OF BIAS: Risk of bias was assessed using the QUADAS-2 tool. METHODS OF DATA SYNTHESIS: We pooled sensitivity/specificity with a bivariate random-effects model and created a summary receiver-operating curve. The main analysis focused on studies reporting on a procalcitonin threshold of 0.10 ng/mL. In addition, we analysed results for all studies, studies with a 0.25-ng/mL and studies with a 0.50-ng/mL threshold. RESULTS: We included 40 of 5450 identified articles, reflecting 192 529 patients of whom 31 480 (16%) had bacteraemia. Of 40 studies, 32 had high risk of bias. The pooled sensitivity for a 0.10-ng/mL threshold was 93% (95% CI: 85-97%) with a specificity of 36% (95% CI: 26-47%). The area under the summary receiver-operating curve for all studies was 0.80 (95% CI: 0.76-0.83%; prediction interval 0.57-0.91). DISCUSSION: A low cut-off value of procalcitonin can be useful to exclude community-acquired bacteraemia, depending on what the treating clinician considers to be an acceptable trade-off between sensitivity and specificity. Procalcitonin may require combination with clinical characteristics for accurate assessment of the risk of bacteraemia and safely reducing unnecessary blood cultures.