CDC may have over-counted opioid overdoses

CDC admits it over-counted opioid overdoses | Pain News Network | Jan 2016 

I’m not so sure they over-counted the total number, because it was lower than simply adding together the category counts.

Drug overdose deaths have increased 137 percent — 200 percent for opioids — since 2000, the federal Centers for Disease Control and Prevention (CDC) announced in its January 1 Morbidity and Mortality Weekly Report (MMWR).

The analysis looked at overall increases in overdose deaths from 2000 to 2014, and focused specifically on increases from 2013 to 2014. The majority (61 percent) of the drug overdoses in 2014 involved some type of opioid, according to the report.  

Some overdose deaths were counted more than once.  “Some deaths involve more than one type of opioid; these deaths were included in the rates for each category (e.g., a death involving both a synthetic opioid and heroin would be included in the rates for synthetic opioid deaths and in the rates for heroin deaths),” the report stated. 

We asked Rose A. Rudd, CDC health scientist and lead author of the report, about the over-counting of overdose deaths.

“Some deaths do include more than one type of drug,” responded Rudd in an email to ADAW.

“In 2014, there were 12,159 deaths involving a natural or semi-synthetic opioid; 3,400 deaths involving methadone; 5,544 deaths involving a synthetic opioid (exclusive of methadone); and 10,574 deaths involving heroin.

There were 28,647 deaths that involved any opioid: this number of deaths does not the sum to the other categories, as deaths do include more than one type of drug.”

I sure hope this gobbledygook wasn’t the verbatim response from a government official. The last sentence is completely muddled, but I think she’s saying that the sum of all the category counts was NOT used to calculate the total.

Here’s their data:

  • 12,159 deaths involving a natural or semi-synthetic opioid
  • 3,400 deaths involving methadone
  • 5,544 deaths involving a synthetic opioid
  • 10,574 deaths involving heroin

28,647 TOTAL deaths that involved any opioid

My calculations show that adding the category counts comes to 31,677, which is very close to 3,000 more than their total number, 28,647,

The difference proves that their total is NOT derived from the category counts. There is only a 10% difference, but their numbers have other problems as well (see CDC: Drug and Opioid Overdose Deaths 2014)

Specific codes

The CDC relied on the National Vital Statistics System multiple-cause-of-death mortality files, which classify drug overdose deaths based on International Classification of Diseases, Tenth Revision underlying cause-of-death codes.

The basic codes are

  • X40–44 (unintentional),
  • X60–64 (suicide),
  • X85 (homicide) or
  • Y10–Y14 (undetermined intent).

Then the type of opioid involved is indicated by a T code (T40.0, T40.1, T40.2, T40.3, T40.4 or T40.6);

  • natural and semisynthetic opioids (including morphine, oxycodone and hydrocodone) are T40.2;
  • methadone is T40.3;
  • synthetic opioids (including fentanyl and tramadol, as well as illicit fentanyl) other than methadone are T40.4; and
  • heroin is T40.1.

If more than one opioid was found, both were listed, accounting for the fact that some deaths were reported more than once.

The increased availability of heroin and its low price compared with prescription opioids, as well as high purity, are “major drivers of the upward trend in heroin use and overdose,” the report stated.


The authors admit that toxicology laboratory tests performed at autopsy vary based on jurisdiction; in addition, in 2013, 22 percent of drug overdose deaths did not include any information on the death certificates about the specific drugs, and 19 percent in 2014 did not include such information.

This accounts for 1/5th of their cases, and without a specified cause, I have to wonder what category they were listed in.

Finally, some heroin deaths might have been misclassified as morphine, because the drugs are metabolized similarly and testing might not have been done that can distinguish between them

As the CDC’s Leonard J. Paulozzi, M.D., told us last year, people who are initiating the use of heroin started with the use of prescription opioids, and “if we can stop feeding that pool now, it will help,” while at the same time saying, “If you have a large cohort of people who are already physiologically dependent on heroin or prescription opioids, those people aren’t going to go away. They’re going to seek drugs, and they will need to get into treatment”

However, the fact is that opioid prescribing has been reduced substantially, and at the same time, heroin use is going up, and the CDC’s main focus is still on reducing prescribing of opioids.    


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  1. Pingback: How to Lie to Yourself and Others With Statistics | EDS Info (Ehlers-Danlos Syndrome)

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