Clinicians use International Normalized Ratio (INR) values to set anticoagulant doses. When they rely on different types of testing equipment to measure INR values, variations in the equipment may lead to variations — and errors — in the INR readings. Furthermore, staff members find it more difficult to maintain competence with several different types of equipment than with one standard type. Errors in testing or interpreting INR values can lead to incorrect dosing of anticoagulants and result in adverse drug events. Select one standard type of INR testing equipment and use it throughout your organization to decrease the risk of such errors.