Have you ever wondered how doctors identify heavy drinking? The CDT test is a unique blood test that measures carbohydrate-deficient transferrin levels to detect chronic alcohol consumption. It’s widely used in medical and legal settings for its reliability.
So, what makes this test so effective? If you’re curious about the test, read on to learn about its accuracy, usage, and the factors that can influence the results.
What is a CDT Test?
A CDT test, or Carbohydrate Deficient Transferrin test, is a specialised blood alcohol test that detects heavy drinking over a longer period. It is known as a better, more reliable alcohol test compared to the traditional blood alcohol test.
Unlike regular blood alcohol tests that measure the amount of alcohol in the blood at a specific time, the CDT test identifies increased levels of a certain protein linked to prolonged excessive alcohol consumption.
This makes it particularly useful for spotting patterns of alcohol misuse. If one has been drinking heavily in recent weeks, the CDT test can accurately reveal it.
How Does a CDT Alcohol Test Work?
A healthcare professional will take a sample of blood from the patient—usually from their arm. The sample will then be sent to the laboratory for analysis.
If the test result shows lower CDT levels in their blood, it indicates that they haven’t been drinking alcohol excessively for at least the past four-week period.
In contrast, the test will result in high CDT levels if the person has been heavy drinking in the same period, indicating chronic alcohol abuse.
For a side note, the CDC categorises heavy drinking as having at least 15 drinks per week for men or eight drinks per week for women.
When is CDT Alcohol Testing Used?
The CDT alcohol test can be used in various scenarios, including:
Assessing Fitness to Drive
The CDT alcohol test is commonly used to evaluate an individual’s fitness to drive, especially for those with a history of alcohol misuse.
Authorities may require this test to confirm that a person has not been engaging in heavy drinking before issuing or reinstating a driver’s license.
For instance, the Australian government states that someone is not fit to hold an unconditional license for both private and commercial standards if there is an alcohol use disorder.
The test provides a clear picture of long-term alcohol consumption, ensuring that drivers are safe and not under the influence over extended periods.
Child Custody and Access Disputes
In child custody and access disputes, the CDT test can help assess a parent’s alcohol consumption patterns.
Courts may request this test to determine if a parent has been drinking heavily, as excessive alcohol use can affect the child’s safety and well-being.
Alongside other assessments, the CDT test provides objective evidence that can influence custody and visitation decisions, ensuring the child’s best interests are prioritised.
Recovery from Alcohol Misuse/Dependency
Healthcare professionals use the CDT test to track a patient’s progress and ensure they are abstaining from heavy drinking. Regular CDT testing offers clear feedback on sobriety, which is important for maintaining long-term recovery and preventing relapse.
Safety and Welfare Cases
In safety and welfare cases, the CDT test determines whether an individual’s alcohol consumption poses a risk to themselves or others.
This is particularly important in jobs where safety is a top priority, such as transportation or construction. The test—alongside other tests like hair, nail, and breath tests—helps verify that individuals in these roles have not been drinking heavily, ensuring they are fit to perform their duties responsibly.
Accuracy of the CDT Blood Test for Alcohol
While studies found that the CDT test is accurate, it doesn’t eliminate the chances of false results, such as
False Negatives
In some people, excessive alcohol consumption does not lead to elevated CDT levels in the blood.
When a healthcare professional suspects heavy drinking despite a negative CDT test, they may explore digital DNA methylation techniques, which analyse blood or saliva samples to detect signs of significant alcohol intake.
False Positives
Biological factors, including genetic variants, female hormones, and advanced liver disease, can lead to falsely elevated CDT levels, especially during the earlier releases of this test.
However, newer tests can now detect specific genetic variants responsible for both false positives and false negatives, as well as patterns associated with liver disease resulting from heavy alcohol consumption.
What Affects the Results of CDT Blood Tests?
The results of a CDT blood test can be influenced by various factors, including:
- Length of drinking
- Health conditions, like certain liver diseases
- Medications
- Genetic differences
- Hormones
- Iron deficiency
- Pregnancy
Frequently Asked Questions
What is a CDT test for?
The CDT test is used for detecting heavy alcohol consumption over a certain period.
How long can a CDT test detect alcohol?
CDT can detect chronic and excessive alcohol use up to four weeks before a blood sample is taken.
What is a positive CDT test result?
When the CDT level is detected as 2.6% or higher, it is considered a positive CDT test result.
Conclusion
The CDT test is a reliable test for detecting heavy alcohol consumption for a certain period. It is especially beneficial for assessing fitness to drive, safety and welfare cases, child custody and access disputes, and recovery from alcohol misuse/dependency.
Are you interested in exploring this test or other types of healthcare assessments for certain purposes? Contact Wells Road Medical Centre for professional help. Our patient-centred medical care will aid your unique needs. Book an appointment now!
