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:Both the methods used in the present work were previously demonstrated to be sufficiently accurate for detecting physiological and pathological changes in serum hepcidin in healthy volunteers and in patients with various disorders of iron homeostasis.(22,7,34,35) Indeed, results with the two methods were essentially concordant from a qualitative point of view, although quantitative differences were observed, e.
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