People over 80 years old are now the fastest-growing age group. Bloodstream infections (BSI) in these patients may present with specific characteristics. The objective of this study was to analyze independent factors affecting in-hospital mortality (IHM) due to BSI in very elderly patients (≥80 years of age) and to compare the clinical presentation of BSI in patients aged 80–89 years versus those aged 90 or more. Retrospective, cross-sectional and observational study of BSI in patients aged 80 years or older. The study used IHM as the primary outcome. Stepwise multiple logistic regression models were used to identify associations between potential predictors and IHM. Of the 336 included patients, 76.8% (n = 258) were in the 80–89-year age group and 23.2% (n = 78) in the 90+ age group; 17.3% (n = 58) of patients died during admission. This outcome was independently associated with quick Sepsis Related Organ Failure Assessment (qSOFA) of 2 or more (adjusted odds ratio [aOR] 4.7, 95% confidence interval [CI] 2.3–9.4; p < 0.001). Other predictors included an origin of BSI outside the urinary tract (aOR 5.5, 95% CI 2.4–12.6; p < 0.001), thrombocytopenia (aOR 4.9, 95% CI 1.8–13.4; p = 0.002), hospital-acquired infection (aOR 3.0, 95% CI 1.2–7.5; p = 0.015), and inappropriate empiric antibiotics (aOR 2.0, 95% CI 1.1–3.9; p = 0.04). IHM was 23.1% in the 90+ age group and 15.5% in patients aged 80 to 89 (p = 0.012). However, the 90+ age group was more likely to have a score of at least 2 on the qSOFA (29.9% vs. 19.1%, p = 0.043) and Pitt bacteremia scales (44.9% vs. 30.2%; p = 0.02), as well as chronic kidney disease (56.4% vs. 36.0%; p = 0.001) and altered mental state (40.3% vs. 25.7%; p = 0.013). In conclusion: A qSOFA score of 2 or more and a BSI originating outside the urinary tract were independent predictors of IHM. The 90+ age group was at higher risk than the 80–89-year age group of having a qSOFA score and Pitt bacteremia score of 2 or more as well as an altered mental state.

Background In older adult patients, bloodstream infections cause significant mortality. However, data on long-term prognosis in very elderly patients are scarce. This study aims to assess 1-year mortality from bacteraemia in very elderly patients. Methods Retrospective cohort study in inpatients aged 80 years or older and suspected of having sepsis. Patients with (n = 336) and without (n = 336) confirmed bacteraemia were matched for age, sex, and date of culture, and their characteristics were compared. All-cause mortality and risk of death were assessed using the adjusted hazard ratio (aHR). Results Compared to controls, cases showed a higher 1-year mortality (34.8% vs. 45.2%) and mortality rate (0.46 vs. 0.69 deaths per person-year). Multivariable analysis showed significant risk of 1-year mortality in patients with bacteraemia (aHR: 1.31, 95% confidence interval [CI] 1.03–1.67), quick Sepsis Related Organ Failure Assessment (qSOFA) score of 2 or more (aHR: 2.71, 95% CI 2.05–3.57), and age of 90 years or older (aHR 1.53, 95% CI 1.17–1.99). Conclusions In elderly patients suspected of sepsis, bacteraemia is associated with a poor prognosis and higher long-term mortality. Other factors related to excess mortality were age over 90 years and a qSOFA score of 2 or more.