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:Randomized controlled trials conducted in a range of surgical settings over the last 25 years have clearly demonstrated that enoxaparin is associated with lower rates of VTE than placebo or elastic compression, without compromising patient safety [5–9].
Category: