Why Would a Drug Test Need Further Testing? A Guide for Agencies and Employers

Administering drug tests as part of workplace policy or compliance checks? Advancements in drug testing are constantly improving their breadth and accuracy — but sometimes, the initial results only tell part of the story. Understanding why a drug test might need further testing is crucial for employers and agencies to maintain a truly safe and productive work environment. Let's explore the situations and nuances that may prompt a deeper dive into drug testing results.

Challenges to Standard Drug Testing

Whether you’re using the convenient, cost-effective option of on-site drug testing or opting for the more in-depth, professionally handled rigor of lab testing, drug screening isn't always straightforward. Several factors can necessitate additional testing to ensure accuracy and fairness even after the results come back.

Some Legal Substances Can Interfere with Test Results

On occasion, medications, foods, and dietary supplements can lead to false positives or ambiguous drug test results. For example, poppy seeds might influence opiate tests, and certain cold medications could trigger a false positive for amphetamines. When these everyday substances interfere, further testing using more sophisticated methods may be necessary to clarify the results.

On-Site Drug Tests May Fall Prey to User Error

The accuracy of a drug test heavily depends on the correct application of testing procedures. User error — such as improper handling of the sample, contamination, or incorrect timing during the testing process — can skew results, leading to false positives or negatives. In such cases, retesting under more controlled conditions is required to ensure the reliability of the results.

Some Substances May Not Show Up on Standard Drug Tests

Standard drug tests generally screen for the most commonly abused substances. However, synthetic drugs, designer drugs, or newer substances on the market might not be detectable with basic testing kits. More specific tests may be needed to identify these substances.

On-Site Testing vs. Lab Testing: How Much Do They Differ?

On-site testing offers fast results and is effective for quickly screening many samples. However, it might not be as thorough as lab testing, which uses advanced techniques like gas chromatography-mass spectrometry (GC-MS) to confirm the presence of drugs and eliminate the likelihood of false positives or negatives.

Lab testing is more precise but also more costly and time-consuming. As such, it’s common for organizations to use on-site testing as a foundational measure, and only turn to professional lab analysis when further testing is required.

When to Request a More Thorough Screening

Requesting in-depth testing for drug screenings is an essential step for employers and organizations aiming to ensure accuracy and fairness in their drug-free workplace policies. Here are some key circumstances when your team should request more thorough testing.

1. After Ambiguous or Unexpected Initial Results: If the results from an initial drug test are unclear or unexpected, in-depth testing can help clarify the findings. For example, if an employee who has no known history of drug use tests positive, a more detailed analysis might be necessary to confirm these results and rule out any false positives.
2. For the Detection of Rare or Synthetic Substances: Standard drug tests typically screen for common substances like marijuana, cocaine, and opiates. However, with the rise of synthetic drugs and novel psychoactive substances, these tests may not detect newer drugs such as synthetic cannabinoids or designer stimulants. If you have reason to suspect an uncommon drug is being abused, more sophisticated lab tests that can identify a wider range of substances are required.
3. For Legal and Compliance Requirements: From education to industrial sectors, certain industries need to drug test for jobs. Among these, some — particularly those regulated by government bodies like the Department of Transportation (DOT) — may have extra-stringent requirements that include confirmed lab testing. When legal or safety issues are at stake, confirming initial test results through more detailed laboratory analysis helps maintain compliance and ensures public safety.
4. For High-Risk Positions: For jobs that involve high-risk activities (e.g., operating heavy machinery, handling sensitive information, or performing healthcare duties), confirming drug test results is crucial. In-depth testing provides an extra level of scrutiny and reassurance that employees in these critical roles are not impaired.
5. Following Treatment and Rehabilitation: In workplaces that support recovery and rehabilitation programs for employees struggling with substance abuse, periodic in-depth testing might be used as a part of the monitoring process to ensure that those employees remain drug-free post-treatment.
6. After an Accident or Incident: If a workplace accident or incident occurs — and particularly if there is a possibility that impairment contributed to the incident — in-depth drug testing is often conducted as part of the investigation to determine if drugs were a factor.

In short, thorough, lab-based testing is useful in any situation that demands absolute clarity and certainty. Performing in-depth testing helps identify the presence of drugs and may even quantify the levels found, which can be important in understanding the extent of an employee’s use or impairment.

Note: Employers should ensure that their testing protocols — including scenarios when they may conduct more comprehensive tests — are clearly documented in drug-free policies. This transparency helps protect both the rights of employees and the integrity of the workplace.

Finding a Partner for All Your Drug Testing Needs

By understanding why a drug test would need further testing, agencies and employers can better navigate the challenges of maintaining a drug-free workplace. When sorting out false positives, detecting newer drug types, or simply ensuring procedural accuracy, additional testing is a critical tool in achieving dependable drug testing results.

However, this all depends on having the right testing partner. From purveying top-quality on-site test kits to verifying results with certified lab testing, a reputable drug testing provider helps guarantee the accuracy and efficiency of your drug testing program. 

Get Reliable Results with Countrywide Testing

Whether you’re interested in on-site testing or more intensive, lab-tested results, Countrywide Testing has drug testing services to suit your needs.

Countrywide offers various drug testing products for workplace testing, healthcare emergencies, law enforcement purposes, and individuals trying to stay clean after rehab. Our on-site drug testing kits are convenient and affordable and ship to you quickly. Plus, our lab is accredited by SAMHSA, ensuring that your organization’s drug testing procedures are thorough, compliant, and reliable.

Want more information on how Countrywide can support your workplace drug testing program? Just contact our team today.