US Drug Test Centers Research Articles

What is a Medical Review Officer, and Why is Having One Invaluable?

Posted: Mar 04 2019

By: Jonathan Baktari, MD / CEO

"...the thrust of the federal policy, as articulated by DOT regulations, appears to be to use a physician as a safeguard against wrongful accusing a person of drug use."
- H. Westley Clark, MD, JD, MPU*

Perhaps the most critical role in any drug testing program is that of the Medical Review Officer, commonly referred to as the MRO. "The MRO's primary role is to determine whether a [legitimate] medical explanation exists for a laboratory-verified positive controlled substance test."[1] The federal Department of Transportation (DOT) rules describe the MRO's role as "an independent and impartial gatekeeper and advocate for the accuracy and integrity of the drug testing process."[2]

In the era of the opioid epidemic and with employers and regulators scrambling in response, the role of the MRO, the gatekeeper, has become even more critical.

The MRO protects a donor from an inappropriate accusation of being an illegal drug user but "the certified MRO [also] protects the company - helping with policies and regulatory issues, as well as providing related services, such as drug test collections, breath alcohol testing services, coordination of laboratory services, laboratory performance testing, and preparation of summary reports for employers."[3]

From a liability perspective, the MRO protects the company from itself – from making employment decisions based on laboratory positive test results which to a qualified medical professional can be explained by the legitimate use of medications. Without an MRO, an employer might base employment action on a laboratory test result explainable by the legal medicines being taken by the donor.

With the current trend, out of concern for employees who use and abuse prescribed medications, employers are expanding their drug test panels to include substances which are typically taken by prescription and, therefore, legal. Merely testing for such drugs or taking employment action due to a positive test raises the potential for employees and applicants to claim that their federal and state disability discrimination rights have been violated.

As the gatekeeper, the MRO not only protects the employee from actions based on a test result easily explained by a prescription, but it protects employers from making mistakes that could cost them a lot of money.

The MRO's Role and How it's Changed With the Opioid Epidemic

Typically, there are three steps that every drug test goes through:

  1. The collection of the sample, be it urine, hair, or oral fluid; commonly split into Bottle A and Bottle B.
  2. The sample analysis, a two-step process consisting of an "initial" screen of the sample either by utilizing an on-site "instant test"[4] or under laboratory analysis, and then followed by a "confirmation" test conducted by a certified laboratory to confirm all non-negative screens.
  3. The MRO reviews the confirmed laboratory results before it is reported out.

These three steps originated back in the late 1980s with the formation of federal drug testing rules. These federal rules form the basis of today's standard of practice in drug testing. The MRO position was adopted from the military's experience with drug testing. Why? Because, although it's recognized that the laboratory can specify what is in the sample that was collected it can't determine how it got there. Was the test result due to illegal or legal use of the substance detected? Making this distinction requires a trained, experienced medical professional.

The logic of this process has also been long recognized by non-regulated drug test programs[5] and legislation directed at non-regulated employers. Here, we focus on the third step of the process, the MRO review.

First, Let's Look at Who Can Be an MRO

According to the federal rules, an MRO "must be a licensed physician (Doctor of Medicine or Osteopathy)."[6] Under federal rules, there are also very detailed requirements for MRO qualification training and requalification training.[7] MRO's must also submit to and satisfactorily complete an examination "administered by a nationally recognized MRO certification board or subspecialty board for medical practitioners in the field of medical review."[8]

Next, it's essential to know that the medical review process does not apply to alcohol tests.[9] Why not? Because the MRO reviews test results for "legitimate medical explanations." With a confirmed alcohol positive result there are no medical explanations to review.

Recognizing that the MRO has many other responsibilities, the MRO's role in reviewing laboratory confirmed non-negative (positive) results include:

(1) Reviewing Copy 2 of the Chain of Custody Form (CCF) to determine if there are any fatal or correctable errors that may require the test to be canceled. The MRO's staff, under the MRO's direct supervision, may conduct this step but only the MRO may verify or cancel a test.

(2) Reviewing Copy 1 of the CCF and ensure that it is consistent with the information contained on Copy 2, that the test result is legible, and that the certifying scientist signed the form. The MRO is not required to review any other documentation generated by the laboratory during their analysis or handling of the specimen (e.g., the laboratories internal chain of custody).

(3) If the copy of the documentation provided by the collector or laboratory appears unclear, the MRO must request that the collector or laboratory send a legible copy.

(4) With limited exception, the MRO conducts a verification interview. This interview must include direct contact in person or by telephone between the MRO and the donor/employee.

(5) Verify the test result, consistent with the federal rules, as:

      (i) Negative; or

      (ii) Cancelled; or

      (iii) Positive, and/or refusal to test because of adulteration or substitution.

The interview with the donor is critical. It's the point in the process where the donor can offer any information that would explain the test result. Typically, this means a prescription for a medication that a treating medical professional has recommended, but it could also include information about foods recently eaten, medical conditions, or any other information the donor thinks could have influenced the result.

The DOT has made it clear that the MRO cannot second guess the prescription issued by a medical professional.[10] The DOT also changed its rules related to how the MRO deals with if the donor's continued use of it (a prescription) could pose a safety issue.

If during the verification interview, in the MRO's "reasonable medical judgment, information provided could or does make the donor unqualified to perform assigned tasks or could pose or does pose a significant safety risk[11] the MRO is authorized, and in some cases required,[12] to report that safety concern to the employer without the donor's consent.

But, under the federal procedures, there is a new requirement for the MRO. Before reporting any information such as a prescription for oxycodone the MRO must allow the donor up to five business days to have the prescribing physician contact the MRO "to determine if the medication [prescribed] can be changed to one that does not make the employee medically unqualified or does not pose a significant safety risk." If after discussions with the prescribing physician, and if the MRO's concerns remain, then the MRO must report those concern to the employer.

Once the MRO is satisfied with all the previous steps, they will make a final determination and release the drug test result to the employer. Upon the drug screen result being released, for positive test results that will likely lead to adverse employment action, the donor has the right to challenge the confirmed test result. This process consists of the donor formally requesting, within a timely fashion, that a separate certified laboratory test the Bottle B portion of the original specimen. Determining who is responsible for paying the fee for the additional testing will depend on what state or federal rules apply and whether the second test confirmed the original result.

Disability Discrimination Rights

Disability discrimination laws, both federal and state, are making the issue of expanded drug panels, the opioid epidemic, and the MRO's role even more critical. Employers who violate these rules have been losing millions of dollars over the past few years in the form of consent decrees, judgments, and jury awards. In some cases, it's because they are not listening to the advice of their MRO[13] or worse yet, didn't use an MRO at all.

The Americans with Disabilities Act (ADA) allows employers to conduct drug testing for illegal drugs.[14] A test to determine the illegal use of drugs is not considered a medical examination. However, when testing for legal substances, the answer is not so straight forward. The Equal Employment Opportunity Commission (EEOC) is responsible for enforcing the ADA. The EEOC has advised that an employer "[g]enerally" may not "ask all employees what prescription medications they are taking" because such questioning "is not job-related and consistent with business necessity."[15] A drug test is considered asking.

A complete discussion of the impact of the ADA, state disability discrimination laws and how prescription medications should be handled is beyond this discussion.  But we can revisit that issue here in the future.

What Can't an MRO Do?

Finally, it's also necessary to understand what an MRO may not do. Recognizing these limitations will help you correctly set expectations. Federal rules[16] provide the following boundaries for MROs:

(a) An MRO must not consider any evidence from tests of urine samples or other body fluids or tissues (e.g., blood or hair samples) that are not collected or tested in accordance with this part. For example, if an employee tells you he went to his physician, provided a urine specimen, sent it to a laboratory, and received a negative test result or a DNA test result questioning the identity of his DOT specimen, you are required to ignore this test result.

(b) It is not an MRO's job to make decisions about factual disputes between the employee and the collector concerning matters occurring at the collection site that are not reflected on the chain of custody form (e.g., pertaining to allegations that the collector left the area or left open urine containers where other people could access them).

(c) It is not an MRO's job to determine whether the employer should have directed that a test occur. For example, if an employee tells you that the employer misidentified them as the subject of a random test or directed them to take a reasonable suspicion or post-accident test without proper grounds under applicable rules, an MRO must inform the employee that they cannot play a role in deciding these issues.

(d) It is not an MRO's job to consider explanations of confirmed positive, adulterated, or substituted test results that would not, even if true, constitute a legitimate medical explanation. For example, an employee may tell the MRO that someone slipped amphetamines into their drink at a party, that they unknowingly ingested a marijuana brownie, or that they traveled in a closed car with several people smoking crack. MROs are unlikely to be able to verify the facts of such passive or unknowing ingestion stories. Even if true, such stories do not present a legitimate medical explanation. Consequently, you must not declare a test as negative based on an account of this kind.

(e) MROs must not verify a test negative based on information that a physician recommended that the employee use a drug listed in Schedule I of the Controlled Substances Act. (e.g., under a state law that purports to authorize such recommendations, such as the medical marijuana laws that some states have adopted).

(f) An MRO must not accept an assertion of consumption or other use of hemp or other non-prescription marijuana-related product as a basis for verifying a marijuana test negative. An MRO also must not accept such an explanation related to consumption of coca teas as a basis for verifying a cocaine test result as negative. Consuming or using such a product is not a legitimate medical explanation.

(g) An MRO must not accept an assertion that there is a valid medical explanation for the presence of PCP, 6-AM, MDMA, MDA, or MDEA in a specimen.

(h) An MRO must not accept, as a legitimate medical explanation for an adulterated specimen, an assertion that soap, bleach, or glutaraldehyde entered a specimen through physiological means. There are no physiological means through which these substances can enter a specimen.

(i) An MRO must not accept, as a legitimate medical explanation for a substituted specimen, an assertion that an employee can produce urine with no detectable creatinine. There are no physiological means through which a person can produce a urine specimen having this characteristic

Don't Have an MRO? Get One.

The increased use and abuse of prescribed medications and the increase of substances added to employer drug testing panels make the need for a medical professional to review drug test results all the more critical. The goal of any testing program must be to prevent employee use of illegal drugs, not legally prescribed medications that do not pose a safety risk in the workplace.

It's abundantly clear that employers cannot afford to not have a Medical Review Officer as a part of their drug screening program. Whether it's required by state or federal law, or solely as a best business practice, the role of a qualified MRO gatekeeper is priceless for both the employee and the employer.

*Dr. Clark is currently the Dean’s Executive Professor of Public Health at Santa Clara University in Santa Clara California. He is formerly the Director of the Center for Substance Abuse Treatment, Substance Abuse and Mental Health Services Administration, U.S. Department of Health and Human Service, where he led the agency's national effort to provide effective and accessible treatment to all Americans with addictive disorders.

[1] Qualifications of Medical Review Officers MROs) in Regulated and Non-regulated Drug Testing

Journal of Occupational and Environmental Medicine: January 2003 - Volume 45 - Issue 1 - p 102-103 See also 49 C.F.R. part 40.123(c).

[2] 49 C.F.R. part 123.


[4] Instant (POCT) drug testing is not approved for federal DOT testing programs. Use of these devices may also be limited by state law.

[5] Caution: state rules may differ and must be implemented into your program if you operate in such a state.

[6] 49 C.F.R. part 40.121(a). State laws may differ. For example, Iowa's mandatory law (Iowa Code 730.5(1)(g)) for employee drug testing is much more open to allowing other medical professionals to serve as medical review officers. Additional medical professionals who can serve as the MRO in Iowa include chiropractor, nurse practitioner, or physician assistant.

[7] While we are focusing here on the MRO it is important to know that the other two steps in the drug testing process also require training or certification: see collector's training requirements at 49 C.F.R part 40.31 and laboratory training and certification at 49C.F.R. part 40.81. Both collectors and laboratories must make their proof of training or certifications available for inspection be any customer.

[8] 49 C.F.R. part 40.121(c)(2).

[9] 49 C.F.R. part 40.3 where the definition indicates that the MRO is responsible for receiving and reviewing laboratory results and evaluating drug test results. State laws may be more direct such as Iowa at Iowa Code sec. 730.5(7)(h).

[10] 82 Fed. Reg. 52235. See also 49 C.F.R. 40.137, which now contains the phrase "you must not question whether the prescribing physician should have prescribed the substance."

[11] See 49 C.F.R. part 40.135(e) and 40.327.

[12] 49 C.F.R. part 30.327. The MRO must report the

[13] In Bates v. Dura Automotive Systems, Inc. 767 F.3d 566 (6th Cir. 2014) the employer eventually lost well over $1 million for, among other things, testing all employees for legal and illegal drugs and requiring all employees to report medications they were taking.

[14] 42 U.S.C. §â€¯12114(d).

[15] See EEOC Enforcement Guidance. 2000, at

[16] 49 C.F.R. part 40.151.

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