The alarming results are clearly the result of erroneous drug tests, which seem to show huge percentages of patients misusing opioids. A previous post, Urine Drug Test Often Gives False Results, explains that the percentages of “misuse” are easily explained by the high rate of “false positives” on the most common urine drug tests.
Without an expensive lab test to verify these results, the conclusions are based on data that’s known to be faulty.
The article never describes what “definitive testing” they were using, but for 634,000 patients, they could not have used the gold standard, because a laboratory test that uses chromatography-mass-spectrometry, costs thousands of dollars.
Definitive testing revealed if patients prescribed an opioid were adhering to their medication or taking another medication that had not been prescribed, going beyond the information gathered from point-of-care testing.
The study included urine samples from 400,334 patients prescribed hydrocodone as their only opioid and 234,273 patients prescribed oxycodone as their only opioid
The researchers screened each sample for
- noroxycodone, and
If a sample tested positive for opioids, they underwent a mass spectrometry and were categorized into one of four groups:
- Positive for only the prescribed opioid
- Positive only for a non-prescribed opioid
- Positive for both the prescribed opioid and a non-prescribed opioid
- Negative for all opioids
Out of the 28,195 samples of patients prescribed hydrocodone that tested positive for other opioids,
- 21.7% were positive for codeine,
- 41.5% for morphine,
- 37.9% for oxycodone,
- 53.2% for oxymorphone, and
- 51.4% for noroxycodone.
For patients prescribed oxycodone who tested positive for any opioid (n=182,823),
- 87.7% were positive for only the prescribed opioid,
- 0.2% for only a non-prescribed opioid,
- 11.5% for both a prescribed and non-prescribed opioid, and
- 0.5% were negative for all opioids.
Out of the 21,461 samples of patients prescribed oxycodone that tested positive for other opioids,
- 11.3% were positive for codeine,
- 38.1% for morphine,
- 45.8% for hydrocodone,
- 49.0% for hydromorphone, and
- 57.0% for noroxycodone.
These seem to be exactly the kinds of errors the previous post warned of: “False positive results were detected over 41% of the time and false negatives over 31% of the time for oxycodone.“
This is also why Dr. Fudin developed his drug-test interpretation app:
REMITIGATE, LLC | Dr. Jeffrey Fudin
Here’s an explanation of the app and how it can help:
App for better Interpretation of Urine Drug Testing