<p>False positive drug test results can occur when employees have certain medical conditions or are taking prescribed medications. It is recommended that all positive drug tests receive<a href="/resources/drug-testing-confirmation-and-mro-services">Confirmation</a> by a certified employee drug testing laboratory. It may also require the attention of a <a href="/resources/glossary/define-medical-review-officer-mro">Medical Review Officer (<abbr title="Medical Review Officer">MRO</abbr>)</a>.</p>