Serum Procalcitonin: An Independent Predictor of Clinical Outcome in Health Care-Associated Pneumonia.

Background: Early prediction of the clinical outcomes for health care-associated pneumonia (HCAP) patients is challenging.

Objectives: This is the first study to evaluate procalcitonin (PCT) as a predictor of outcomes in HCAP patients.

Methods: We conducted an observational study based on data for HCAP patients prospectively collected between 2011 and 2014. Outcome variables were intensive care unit (ICU) admission and 30-day mortality. PCT was categorized into three groups: <0.5, 0.5-2.0, and >2.0 ng/ml. We analysed multiple variables including age, sex, comorbidities, clinical findings, and PCT group to assess their association with outcomes.

Results: Of 245 HCAP patients, 99 (40.4%) were admitted to an ICU and 44 (18.0%) died within 30 days. The median PCT level was significantly higher in the ICU admission (1.19 vs. 0.4 ng/ml; p < 0.001) and 30-day mortality (3.3 vs. 0.4 ng/ml; p < 0.001) groups. In multivariate analysis, high PCT (>2.0 ng/ml) was strongly associated with ICU admission [odds ratio 3.734, 95% confidence interval (CI) 1.753-7.951; p = 0.001] and 30-day mortality (hazard ratio 2.254, 95% CI 1.250-5.340; p = 0.035). In receiver operating characteristic analysis, PCT had a poor discrimination power regarding ICU admission [0.695 of the area under the curve (AUC)] and a fair discrimination power regarding 30-day mortality in HCAP patients (0.768 of the AUC).

Conclusions: High PCT on admission was strongly associated with ICU admission and 30-day mortality in HCAP patients. However, application of PCT alone seems to be limited to predicting outcomes.