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:Family history of SD was present when the patient reported a parent or sibling who died unexpectedly and suddenly before the age of 80 years.(10) Hypertension, hypercholesterolemia, and diabetes were scored based on previous diagnosis and initiation of therapy.
Category: