Georgia Insurance Commissioner John Oxendine has launched an inquiry into how Georgia health insurers calculate payments to physicians for out-of-network care. Oxendine has ordered 18 major insurers to report how they set reimbursement rates for service delivered outside their networks. He said he also wants to know which, if any, insurers use the Ingenix database, a focus of lawsuits that allege that data have been manipulated to shortchange patients and doctors.