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:Although a score of 9/10 has been recommended as an appropriate cut-off for screening PPD,([19]) based on current evidence for the German-speaking version a cut-off of 10/11 is used to maximize sensitivity and specificity.
Category: