Short versus long duration antimicrobial treatment for community-onset bacteraemia: A propensity score matching study

The efficacy and safety of short-course intravenous (i.v.) antimicrobial therapy for bloodstream infections is unknown. Therefore, a retrospective 8-year cohort study including 1431 hospitalised adults was conducted to compare the outcomes of patients receiving short-course (5-10 days) and long-course (11-16 days) i.v. antibiotic therapy for community-onset bacteraemia. Of 1010 patients who received short-course therapy, 726 were matched with 363 patients in the long-course group through propensity score matching at a ratio of 1:2 based on independent predictors of 30-day mortality identified in the multivariate regression model. Following appropriate matching, similarities between the two groups in the proportion of baseline characteristics (age, sex, major co-morbidities, co-morbidity severity, bacteraemia severity at onset and major bacteraemia sources) and 30-day crude mortality rate after bacteraemia onset were observed. Notably, clinical outcomes within 30 days after the end of i.v. therapy, in terms of proportions of post-treatment overall infections (2.2% vs. 6.1%; P = 0.001), infections caused by antimicrobial-resistant pathogens (ARPs) (1.7% vs. 4.4%; P = 0.007), and thereby post-treatment crude mortality (1.4% vs. 3.6%; P = 0.009), were lower in the short-course group. In conclusion, for adults with community-onset uncomplicated bacteraemia, short-course (5-10 days) i.v. antibiotic treatment did not result in an increased risk of mortality but instead decreased the odds of overall and ARP infections after the treatment course.