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Check out. Continue shopping. Drug test detection times, detection level, cut off levels, abbreviations and time that drugs can be detected on a urine drug test or saliva drug test.
May 31, 2024 · Find out how to read urine drug test results. Our detailed guide helps you understand each result and what it means for you.
A faint T line with a visible C line is always a negative drug test result, on any drug test kit on which two lines is a negative result, ie no drugs detected above the cut off levels for the drug test, on the sample being tested. Faint lines can just be a characteristic of certain drug test membranes, remember they are all testing to different ...
You can view test results in your GP health record using the NHS App or by logging into your account on the NHS website. You can create an account if you do not already have one. To view your test results online, you must be: registered with a GP surgery. aged 16 or over.
- General
- Urine Testing
- Hair Testing
- Oral Fluid Testing
- Nail Testing
- Conclusion: Find A Great Lab
1. Interpretation
A qualified and trained toxicologist (a chemist, biochemist, medic, pharmacist, forensic scientist or similar) should interpret every single testto rule out any extenuating circumstances that could affect the results. Without trained interpretation, it is impossible to draw a valid conclusion. Interpretation, though, should be shared with the requester of the test. A lawyer may not have the expertise or knowledge to judge whether the subject’s behaviour is consistent with the results, thus ne...
2. Sample collection and chain of custody
Every test should be subject to stringent processes for sample collection, which will avoid the risk of mistakes or tampering. The chain of custody- which involves the documentation and traceability of the entire testing process - everything that was done, who it was done by, and a timestamp for every part of the process. This ensures that we can reconstruct the entire analysis for court proceedings, with 100% confidence and accuracy.
3. Time between collection and test
The longer the time that passes between collection and test, for certain tests, the more likelihood there is of external factors (like temperature) affecting the sample. This tends to affect liquid samples more than hair samples: the stability of the latter can be advantageous where time is an issue.
4. Hydration/dilution
In some instances, excessive water consumption can lead to a donor’s urine sample becoming diluted, thereby reducing the quantity of a drug that can be detected and causing the concentration detected to fall below the relevant cut-offs. This will generate a false negative - although the laboratory should be capable of checking the concentration of the urine through testing the specific gravity or the urine’s creatinine concentration.
5. Tampering
Because of the level of privacy required for a donor to produce a sample, it is possible for them to switch samples, or dilute them with water. Donors could even adulterate urine samples with nitritesto minimise the chances of drugs being detected.
6. Metabolic profile
Humans are all built differently, and that includes our metabolism. Active metabolism won’t hide drugs in the system, but it can affect the quantities. It is possible that a screening immunology test could test ‘positive’ as a result of the parent drug and its metabolites generating a single, combined result. The LC-MS/MS confirmation test, however, will deliver results for the drug and metabolites that are allbelow their respective cut-off levels.
8. Is it the right head?
Is the hair sample actually being taken from the right person? On the day, the trained collector should ask the donor for official photo ID, which will confirm that the test is correct and will help protect the chain of custody.
9. External contamination
Contamination can occur either through sebum or sweat, or via direct contact. It may be that the donor has been around someone smoking marijuana, or has accidentally come into contact with cocaine, which they’ve transferred from their hands to their hair. A reputable testing lab will be able to differentiate between external contaminationand genuine drug use.
10. The choice of head or body hair
While head and body hair are equally accurate as markers of drug use, the two differ in terms of the timeframe of drug usethat they cover. Because of the biology of body hair, it cannot be used for sectional analysis like head hair can.
14. Recent drug use
The detection windowfor oral fluid testing is 0-2 days, meaning it is only suitable for testing “in the moment”. This means that a donor could, in theory, simply stop using a drug a few days before the test to ensure a positive result, and continue to take the drug after the test is over.
15. Screening vs. confirmation testing
A screening (immunoassay) test may give a positive result - but this positive simply means that the sample should be sent to the lab for confirmation(LC-MS/MS) tests. It may be that the LC-MS/MS then reveals a negative result: the screening could be positive purely because of the shape of the molecule of an innocuous substance similar to the drug, or because the levels of the drug found are below the cut-off levels. As an example, some codeine-based over the counter pain medications may give...
16. pH
The pH of a donor’s oral fluid can affect the proportion of various drugs that will be ionised, and therefore that will be detectable. One study showedthat increasing production of oral fluid by chewing citric acid candy, chewing gum or some other agent could, for example, “lower concentrations of codeine by about two- to six-fold.
17. Fingernails vs. toenails
As toenails grow more slowly than fingernails, a toenail sample will be able to reveal whether a drug has been used in roughly the previous twelve months. As fingernails grow slower, analysis of fingernail testing for drugswill only be able to show use in roughly the last six months.
18. Incorporation directions
The keratin in nails grows in two directions: both in length, as fingernails grow from the root, and thickness, with keratin being added to the underside of the nail as it grows.
19. Drug incorporation rates
Different drugs are incorporated into both fingernails and toenails at different rates - and these rates differ from the rate of incorporation into hair. A qualified laboratory will take these differing rates into consideration when analysing results.
All of this may make it sound like drug testing is more effort than it’s worth, but that’s certainly not the case. The important thing to remember is that a great lab will take all of these factors into account when collecting, testing and analysing: so it’s vital to find a great lab. Before making the final decision on a drug and alcohol testing p...
No matter what type of drug test you are taking - urine, saliva, hair, or blood- the results will be reported in one of three ways: positive, negative, or invalid. Each result type has specific implications, and knowing how to read and interpret them is essential for making informed decisions.
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Feb 23, 2022 · 23rd Feb 2022 • 6m read. Interpreting abnormal urine drug screen results. Opioids, benzodiazepines, cocaine, cannabis - a urine drug test can detect if your patient recently consumed any of them. How are opiates and opioids different? Do both trigger a positive opioid screen? How can you estimate how long a drug is detectable in urine?
