Positive Rate and Utility of Blood Culture among Nursing and Healthcare-associated Pneumonia Inpatients: A Cross-sectional Study

OBJECTIVE: Although blood cultures to identify the presence of bacteremia are recommended for nursing- and healthcare-associated pneumonia (NHCAP), the incidence of true bacteremia and the relationship between true bacteremia and the outcome remain unclear. Physicians can therefore sometimes be confused regarding whether or not blood cultures should be obtained for NHCAP patients. This study assessed the incidence of true bacteremia and the relationship between true bacteremia and the outcome of NHCAP in a Japanese hospital setting. METHODS: We retrospectively analyzed NHCAP patients hospitalized between April 2016 and March 2021. The primary outcome was the incidence of true bacteremia in blood cultures. The incidence of true bacteremia was also examined according to quick Sequential Organ Failure Assessment (qSOFA) and A-DROP scores. In addition, we compared the incidence of true bacteremia between survivors and non-survivors. RESULTS: In total, 205 patients were included in this study. Blood cultures were obtained from 150 of the 205 patients (73.2%). Positive blood cultures were detected in 26 patients (17.3%), of which only 8 cases (5.3%; 95% confidence interval, 2.3-10.2%) were considered true bacteremia. Trend analyses for the incidence of true bacteremia according to qSOFA and A-DROP scores did not show any statistically significant results (p=0.49 for qSOFA; p=0.14 for A-DROP). The proportion of true bacteremia cases did not differ significantly between survivors and non-survivors. CONCLUSIONS: The incidence of true bacteremia among NHCAP patients was very low. A strategy for determining indications for obtaining blood cultures from NHCAP patients needs to be established.