**5.3 Risk factors associated with early versus late onset infections**

 Studies on infections of ICD systems suggest that there are differences between risk factors as to whether they increase the risk of early onset infections (within 6 months of implantation) or later infection. In one study, epicardial leads and postoperative wound complications, such as pocket hematoma, were associated with early infection while the length of hospitalization and chronic obstructive pulmonary disease was associated with later infection. A more general interpretation of this has been suggested; circumstances that increase the probability of pocket contamination in the postoperative period are more likely to be associated with early onset infection, while overall poor health of the patient increases the risk of late onset infection [33]. Attempts have also been made to find useful differences between pathogens related to early versus late onset infections, yet without clinically significant findings [34]. Although these efforts to describe patterns, typical of early versus late infections, can increase the understanding of the pathogenesis and prevention, there are yet no simple implications for management or other obvious clinical benefits of making such a division.
