Risk factors for morbidity and mortality of bloodstream infection in patients undergoing hemodialysis: A nested case-control study

Abstract

Background: Infection is the leading cause of morbidity and the second most frequent cause of mortality among patients on renal replacement therapy. A major morbid event in this population is hospitalization because of infection. The aim of this study was to investigate the risk factors for morbidity and mortality related to bloodstream infection (BSI) among patients on hemodialysis. Results: Risk factors for morbidity and mortality related to BSI in patients on hemodialysis were investigated retrospectively by nested case-control, from January 2010 to June 2013. Patients were divided into two groups: those who progressed to hospitalization or death due to BSI (Group 1) and those who developed BSI, but did not progress to the same outcome (Group 2). Data were collected through consultation of patient records. For statistical analysis, logistic regression was used. There were 32 patients in Group 1 and 61 in Group 2. Logistic regression verified that, for each year of age, the chance of death or hospitalization for BSI increased 1.05 times [95% confidence interval (CI): 1.02-1.09]. Patients with BSI caused by Staphylococcus aureus had an 8.67 times higher chance of progressing to death or hospitalization (95% CI: 2.5-30.06). The isolation of multiresistant microorganisms in blood cultures of hemodialysis patients increased morbidity and mortality by 2.75 times (95% CI: 1.01-7.48). Conclusion: Independent risk factors for morbidity and mortality among patients after developing BSI during hemodialysis were: age, blood culture positive for S. aureus, and antibiotic resistance. Control measures to prevent microbial dissemination, primarily the multiresistant ones, should be intensified in this population. More studies are needed to standardize specific measures not yet classically standardized, such as collection of surveillance culture samples, contact precautions, and decolonization.