In a move to balance the concern regarding rising utilization while still ensuring physician autonomy on access to ordering cardiac tests and procedures, the American College of Cardiology collaborated with the American Society of Echocardiography to develop its Appropriate Use Criteria (AUC) for Echocardiography in 2007, and were updated in 2011. AUC were created by using the modified RAND appropriateness method. Studies applying AUC to TTE orders at single centres in the US found inappropriate TTE rates in ambulatory (outpatient) care ranging up to 35%.