256 Chapter 11 Challenges in the management of S. aureus bacteremia can also arise in the form of identifying which patients are more at risk for dying than others. Ideally, in such a heterogenous disease, risk factors for mortality are known for every individual patient, guiding treatment plans and communication with patients and their relatives. Previously identified risk factors for mortality in patients with S. aureus bacteremia include increasing age, infective endocarditis, hemodialysis dependence and persistent bacteremia [16]. On top of these, female sex has been suggested as risk factor for mortality in several studies, even with reports of an increased mortality risk of 30% in females relative to males [17-19]. However, other studies did not find any sex-related mortality difference [20, 21]. Hence, the true influence of female sex on mortality remains unknown. Perhaps, the historical tendency to include fewer female patients in scientific studies has contributed to this knowledge gap. In chapter 9, we analyzed sex-differences in a large prospective cohort of S. aureus bacteremia patients in the United States. We found no difference in mortality between females and males. However, other characteristics differed significantly. For example, females were more often black, hemodialysis dependent, more likely to have implanted foreign material, and more likely to have used corticosteroids in the past month compared to males. Females were also more often infected with MRSA (as opposed to MSSA), compared to males. Although the aforementioned differences between females and males are interesting, they are pre-existing upon entry and therefore not potential targets for improvement. This in contrast to differences in disease management, which were also notably present. Transesophageal echocardiography was performed less often in females. Furthermore, females were treated with a shorter median duration of antibiotics compared to male patients. The interpretation of these differences in disease management is complex, since males were also shown to have higher rates of metastatic infections, and different directions of causality are therefore plausible. More invasive diagnostic tests (i.e., transesophageal echocardiography) in males could have led to more frequent identification of complicated disease, and subsequently longer courses of antibiotics. Conversely, males could have truly had more complicated disease and therefore more often a true indication for transesophageal echocardiography. A sexdriven bias in management is therefore not downright proven in our study, but the findings warrant additional research to identify the underlying mechanisms of these discovered differences. Given the contradictory reports in literature with regard to female sex as risk factor for mortality, we assessed all studies reporting mortality in S. aureus bacteremia stratified by sex in chapter 10. In this systematic review and meta-analysis, 89 studies with a total of 132,582 patients with S. aureus bacteremia were included. An increased odds of death of 18% in females relative to males was identified in this study. This difference remained when only studies that adjusted mortality for
RkJQdWJsaXNoZXIy MTk4NDMw