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:Our results showed that the treatment response of the 5 mg/day vortioxetine group was greater than the placebo group, and the pooled ES of the studies (Katona et al. 2012; Mahableshwarkar et al. 2013; Henigsberg et al. 2012; Jain et al. 2013) demonstrated the antidepressant efficacy of vortioxetine.
Category: