The Prognostic Factors of Bloodstream Infection in Immunosuppressed Elderly Patients: A Retrospective, Single-center, Five-year Cohort Study

Introduction: Elderly patients with immunosuppressive status may have increased risk of mortality. At present, few studies have explored the clinical characteristics of the elderly immunosuppressed population with bloodstream infection. Our objectives were to evaluate the prognostic factors in immunosuppressed elderly patients with bloodstream infection.Methods: Three hundred and seventy-six elderly patients who were diagnosed with bloodstream infection in immunosuppressive status while receiving treatment in our hospital were selected from 2015 to 2019. The demographic data, underlying diseases, comorbidity, inducement, complications, pathogen sources, etiologies and the antibiotic therapy were analyzed between 90-day survival groups and 90-day mortality groups. The prognostic factors of 90-day mortality were evaluated by univariate logistic regression analysis and multivariate logistic regression analysis.Results: The clinical characteristics of 376 immunosuppressed elderly people diagnosed with bloodstream infection were analyzed, and among those people about 111 were 90-day mortality. By univariate logistic regression analysis and multivariate logistic regression analysis, we found ICU admission (OR: 2.052, 95%CI: 1.088-3.871, p=0.026), the decrease in BMI (OR: 0.307, 95% CI: 0.130-0.723, p=0.007), coronary heart disease (OR: 2.028, 95%CI: 1.078-3.816, p=0.028), biliary infection (OR: 4.406, 95%CI: 1.794-10.821, p=0.001) and the use of tigecycline (OR: 2.480, 95%CI: 1.195-5.147, p=0.015) were significantly different between the 90-day survival and 90-day mortality groups.Conclusion: ICU admission, coronary heart disease, biliary infection, and the use of tigecycline were the independent prognostic risk factors of 90-day mortality in immunosuppressed elderly people, and the decrease in BMI was the protective factor, which would have the benefit of discriminating the prognostic factors in immunosuppressed elderly people with bloodstream infection.