The system, which has 10 hospitals in Illinois, aims to reduce elective surgeries by 50% for patients whose surgeries would require overnight care, starting later this week, said Dr. Jeff Bahr, chief Aurora Medical Group officer, during a call with reporters Monday. The hospitals will look at the urgency of procedures and how many resources would be needed to do them, among other things, in deciding which should be delayed. Cancer treatments will not be postponed.