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:This study was conducted and reported using the following checklists: AMSTAR (Assessment of Multiple Systematic Reviews) [15] and PRISMA Statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) [16] (S1 Appendix).
Category: