2022 Volume 37 Issue 2 Pages 48-56
Time to positivity (TTP) of blood cultures is a predictor of clinical outcomes for bloodstream infection (BSI). This retrospective study aimed to investigate the relationship between the TTP and clinical outcomes in patients with Enterobacteriaceae BSI and to identify prognostic factors. We included 245 patients with Enterobacteriaceae BSI identified over a 1-year period in Kainan Hospital in Japan. TTP and other clinical parameters were determined and analyzed. The standard cut-off for TTP was 11 h for the assessment using receiver-operating characteristic curve analysis (sensitivity, 0.917; specificity, 0.687; area under the curve, 0.841). The cumulative survival after the blood sample collection day until day 14 was calculated using the Kaplan-Meier method. Furthermore, the TTP and other clinical parameters associated with the 14-day mortality of patients with Enterobacteriaceae BSI were examined using Cox proportional hazards regression analysis. Two factors, including TTP ≤11 h (hazard ratio, 19.6; p=0.006) and Pitt bacteremia score (PBS) ≥4 points (hazard ratio, 14.6; p<0.001), were significant independent prognostic factors for 14-day mortality in multivariate analysis of the patient cohort. Two variables, assigned 1 point each, were used to create a prognostic score (PS). The 14-day survival was significantly worse with an elevated PS: 99.4%, 93.8%, and 33.3% in PS of 0 (n=155), 1 (n=81), and 2 (n=9), respectively. The risk of mortality in patients with Enterobacteriaceae BSI may be estimated using a risk score derived from the acute illness severity, as estimated based on TTP and PBS.
