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:[6,7] This is a challenge because of the long distances to travel for consultations, and thus patients are unlikely to come back for treatment for something like OSSN unless it is in its advanced stages significantly impacting their quality of life, at which point early interventions are no longer possible.[6,8] A 2010 study in Tanzania showed that 40% of operated suspected OSSN cases were managed outside of major hospitals where better facilities and quality of care was available, because of difficulty of traveling to and accessing these centers.
Category: