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:Patients dialyzing at the facilities we studied had lower hemoglobin concentrations on average, and more patients had concentrations below the threshold of 10 g/dL at any given time, findings noted by others [6, 7, 11, 12] that are
Category: