The utility of serial procalcitonin measurements in addition to pneumonia severity scores in hospitalised community-acquired pneumonia: A multicentre, prospective study.

Objectives: The usefulness of serial procalcitonin (PCT) measurements for predicting the prognosis and treatment efficacy for hospitalised community-acquired pneumonia (CAP) patients was investigated.

Methods: This prospective, multicentre, cohort study enrolled consecutive CAP patients who were hospitalised at 10 hospitals in western Japan from September 2013 to September 2016. PCT and C-reactive protein (CRP) were measured on admission (PCT D1 and CRP D1), within 48-72 h after admission (PCT D3 and CRP D3), and within 144-192 h after admission. CURB-65 and the Pneumonia Severity Index (PSI) were assessed on admission. The primary outcome was 30-day mortality; secondary outcomes were early and late treatment failure rates.

Results: A total of 710 patients were included. The 30-day mortality rate was 3.1%. On multivariate analysis, only PCT D3/D1 ratio >1 [odds ratio (95% confidence interval): 4.33 (1.46-12.82),P = 0.008] and PSI [odds ratio (95% confidence interval): 2.32 (1.07-5.03), P = 0.03] were significant prognostic factors. Regarding treatment efficacy, PCT D3/D1 >1 was a significant predictor of early treatment failure on multivariate analysis. PCT D3/D1 with the PSI significantly improved the prognostic accuracy over that of the PSI alone.

Conclusions: PCT should be measured consecutively, not only on admission, to predict the prognosis and treatment efficacy in CAP.