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:The results demonstrated an increased risk of type 2 diabetes in shift
workers compared with day workers (OR 1.35, 95% CI 1.05–1.75) (Suwazono et al., 2006).
Category: