Indianapolis-based insurer WellPoint has announced it is halting reimbursement payments to hospitals and doctors for 11 medical errors considered preventable. The 11 errors identified by WellPoint are those that have been defined as preventable by the Centers for Medicare and Medicaid Services and the National Quality Forum. Officials will use several methods for identifying the errors, including comparing a patient's diagnosis and condition upon admission to a hospital with the treatment received during the hospital stay.