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:Eligible for inclusion were male patients diagnosed with schizophrenia or schizophreniform disorder according to DSM IV criteria after a Comprehensive Assessment of Symptoms and History interview (CASH) [14] and by consensus between two senior psychiatrists who were blind to the expression results at the time of diagnosis.
Category: