Aim: This study was performed to investigate serum procalcitonin (PCT) and albumin (Alb) as prognostic biomarkers in elderly patients at risk of bacterial infection. Methods: Serum PCT was measured in 270 hospitalized patients (mean age, 77.4 years) with suspected bacterial infection. The PCT-negative (<0.5 ng/mL) and PCT-positive (!0.5 ng/mL) groups comprised 155 and 115 patients, respectively. Logistic regression analysis was performed with various clinical laboratory test values as

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... t variables and PCT positivity/negativity as the dependent variable. Results: C-reactive protein (CRP) was the only independent variable significantly associated with PCT positivity/negativity. In the survival analysis, the 30-day in-hospital death rate was significantly higher in the PCT-positive than -negative group. Within the Alb-positive group (>2.5 g/dL), no significant difference in survival was observed between the PCT-positive and -negative groups. However, within the Alb-negative group ( 2.5 g/dL), the survival rate was significantly lower in the PCT-positive than -negative group. PCT was strongly associated with CRP and Alb, and having both PCT positivity and Alb negativity was a prognostic factor for elderly people at risk of bacterial infection. Conclusions: Combined measurement of PCT with Alb is expected to be a valuable tool to assess prognosis in elderly people at risk of bacterial infection.