A licensed physician with a history of substance abuse diagnostic work. Per DOT regulations all DOT drug screens must be reviewed by an MRO. Many states also require an MRO review, and this service is available for non-DOT testing if desired. Services include the interpretation and evaluation of test results from confirmed positive, adulterated and substituted specimens in addition to the employee's medical history or other relevant biomedical information necessary to determine if there is a legitimate explanation for a confirmed positive test.