Clinical Characteristics and Predictors of Mortality in Elderly Patients with Bloodstream Infections: A 12-Year Retrospective Cohort Study.

BACKGROUND

Bloodstream infections (BSIs) in elderly patients are associated with heightened mortality risks. This study aimed to characterize clinical profiles and identify predictors of mortality in this at-risk population.

METHODS

In this 12 years retrospective cohort study, elderly patients (≥65 years) with BSI (mean age 89.9 ± 8.5 years), admitted to a tertiary geriatric hospital in Beijing, China from December 2011 to February 2024, were enrolled. Comprehensive analyses of clinical characteristics, microbiological profiles, and laboratory parameters were performed. Multivariable logistic regression analysis was performed to assess mortality-associated risk factors. Additionally, receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic utility of various laboratory biomarkers.

RESULTS

A total of 527 elderly patients (mean age 89.9 ± 8.5 years) were included in the final analysis, among whom 440 (83.5%) survived and 87 (16.5%) died. Multivariate analysis revealed that prolonged mechanical ventilation was strongly associated with the highest risk of all-cause mortality, with escalating risks observed in duration-dependent patterns:1-30 days (odds ratio [OR], 12.70; 95% confidence interval [CI], 5.86-29.00; P < 0.001) and 31-90 days (OR, 3.21; 95% CI, 1.53-6.89; P = 0.002). Additional independent risk factors for all-cause mortality included: the use of central venous catheterization (1-60 days) (OR, 2.56; 95% CI, 1.05-6.72; P = 0.045) and urinary catheterization (1-60 days) (OR, 2.28; 95% CI, 1.13-4.62; P = 0.021), chemotherapy or radiotherapy (OR, 3.25; 95% CI, 1.42-7.43; P = 0.005). ROC curve analysis demonstrated platelet count as the most discriminative prognostic marker, with an area under the curve (AUC) of 0.79, a Youden index of 0.53, sensitivity of 58.3%, and specificity of 94.2%.

CONCLUSIONS

Prolonged invasive medical interventions, including mechanical ventilation, central venous catheterization, and urinary catheterization, as well as chemotherapy or radiotherapy, were independently associated with higher mortality in elderly BSI patients. These findings highlight the need for risk-stratified management strategies to optimize outcomes in these elderly patients.