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:In the only other study, to our knowledge, to examine antibiotic timing and its effect on persistent bacteremia, no significant difference was found in the timing of vancomycin initiation in patients with pMRSAB and patients with npMRSAB.(3) We did not detect an association between vancomycin use and pSAB in our study.
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