Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Importantly, nosocomial candidemia is associated with an unacceptably high mortality ranging between 30% and 50% (Gudlaugsson et al., 2003; Wisplinghoff et al., 2004; Zaoutis et al., 2005).
Category: