Mortality predictors and definition proposal for complicated coagulase-negative Staphylococcus bacteraemia: a multicentre prospective cohort study.

OBJECTIVES

The study aimed to explore a definition for complicated coagulase-negative staphylococci bloodstream infections (CoNS BSIs) and to identify predictors for mortality.

METHODS

A prospective cohort study was conducted from October 2016 to March 2017 in 26 Spanish hospitals. Complicated CoNS BSI criteria included lack of early catheter removal in catheter-related cases, foreign indwelling implant, persistent bacteraemia, fever ≥72 hours on active therapy, metastatic infection or deep-seated focus, and infective endocarditis. Independent predictors for 30-day mortality were evaluated by Cox regression, and the impact of the definition of complicated bacteraemia was assessed.

RESULTS

Overall, 445 CoNS BSI cases were included; catheter-related infections were predominant (336/445, 75.5%). Complicated bacteraemia was identified in 240 of 445 patients (53.9%); 30-day mortality in complicated and uncomplicated cases was 53 of 240 (22.1%) and 24/205 (11.7%), respectively (p 0.004). Predictors of 30-day mortality identified in the multivariate analysis included age (hazard ratio [HR]: 1.03, 95% CI: 1.01-1.05), cerebrovascular disease (HR: 2.58, 95% CI: 1.45-4.58), immunosuppressive therapy (HR: 2.16, 95% CI: 1.22-3.84), SOFA score (HR: 1.09, 95% CI: 1.03-1.16), and complicated bacteraemia (HR: 2.14, 95% CI: 1.29-3.53). A catheter-related source of bacteraemia was found to be protective (HR: 0.49, 95% CI: 0.30-0.80). When specific criteria to define complicated bacteraemia were included, fever ≥72 hours was associated with an increased risk of death (HR: 2.52, 95% CI: 1.52-4.17) and early catheter removal was protective (HR: 0.47, 95% CI: 0.26-0.83).

DISCUSSION: A high proportion of patients presented complicated bacteraemia according to the proposed criteria; these patients had higher hazards for mortality. Other mortality predictors were identified. Further studies would be needed to validate the proposed criteria.