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 participants completed the Hand10, the DASH-JSSH [9, 10], and the Revised Hasegawa Dementia Scale (HDSR) questionnaires [11] twice, with an average interval of 10 days.
Category: