CDC Over-Counted Opioid Overdoses

By Alison Knopf, Editor of Alcoholism & Drug Abuse Weekly

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.”

That is not to discount the severity of the opioid epidemic, and the increase in heroin and illicit fentanyl use and overdose deaths. Heroin and illicit fentanyl (not the prescribed medication) were responsible for most of the increase, the report stated. There was a particularly sharp increase in deaths involving synthetic opioids (other than methadone), which, the report said, was in line with law enforcement reports of an increase in illicit fentanyl on the streets. However, pharmaceutical fentanyl cannot be distinguished from illicit fentanyl in death certificates.

Between 2013 and 2014, overdose rates involving methadone were unchanged, but deaths involving opioid pain relievers increased 9 percent, deaths involving heroin increased 26 percent and deaths involving synthetic opioids (other than methadone) increased 80 percent.

“These findings indicate that the opioid overdose epidemic is worsening,” the report stated. “There is a need for continued action to prevent opioid abuse, dependence, and death, improve treatment capacity for opioid use disorders, and reduce the supply of illicit opioids, particularly heroin and illicit fentanyl.”

The greatest increases were in 25–44-year-olds and people 55 and over; in whites and blacks; and in the Northeastern, Midwestern and Southern regions of the United States.

Hardest-hit states

The report singled out the five states with the highest rates of drug overdose deaths in 2014: West Virginia (35.5 deaths per 100,000), New Mexico (27.3), New Hampshire (26.2), Kentucky (24.7) and Ohio (24.6). In addition, states with statistically significant increases in the rate of overdose deaths from 2013 to 2014 included Alabama, Georgia, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Mexico, North Dakota, Ohio, Pennsylvania and Virginia.

Specific codes

The CDC relied on the National Vital Statistics System multiplecause-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 increase in heroin overdoses mirrors large increases in heroin use across the country, the report stated, and it adds that heroin use is “closely tied to pain reliever misuse and dependence.”

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.


In addition to counting deaths more than once, there were other limitations to the study. 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. 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.

Message still prescription opioids

The conclusion of the report was the same message the CDC has been promoting (as it has been tasked with by the White House) — to reduce the prescribing of opioids. 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. 

The MMWR was posted online as an early release December 18, shortly after the CDC announced it would issue draft guidelines on opioid analgesic prescribing for primary care providers.

This article is republished with permission of Alcoholism & Drug Abuse Weekly, which provides news and analysis of federal and state public policy developments, private sector business developments, and provider issues and innovations in addiction treatment.