US opioid use not declined, despite focus on abuse and awareness of risk

Use of prescription opioids in the United States has not substantially declined over the last decade, despite increased attention to opioid abuse and awareness of their risks, finds a study published by The BMJ today.

The results show that, although opioid use and average dose of opioids levelled off after a peak in 2012-13, all patient groups had a higher average daily dose in 2017 than in 2007, and use was particularly high among patients with a disability.

The US has the highest rate of opioid use in the world, consuming seven times more prescription opioids per person than the UK. An average of 40 people die in the US every day from prescription opioid overdose, and opioid use has been declared a public health emergency.

Recent studies have focused on the sale and supply of opioids, but information on patient demographics is limited. As a result, relatively little is known about opioid use among people outside of the government-provided Medicare insurance scheme.

So a team of US based researchers used data from a national database of medical and pharmacy claims to examine trends in opioid use among 48 million people with health insurance at any time between 2007 to 2016.

Participants were covered either by commercial (private) insurance, or by Medicare Advantage (cover offered by private insurers on behalf of Medicare).

The majority of non-elderly people in the US are covered by commercial insurance, often through their employer or a family member's employer. Most US citizens aged 65 and older are eligible for Medicare, while others are eligible owing to permanent disability.

The research team took certain information into account, such as age, sex and place of residence, race or ethnicity, and type of medical coverage.

To allow for comparison of doses across different drugs they used conversion factors from the Centers for Disease Control and Prevention to translate prescriptions of each drug into milligram morphine equivalents (MME).

The researchers found that although the rate of opioid use and average dose of opioids levelled off after a peak in 2012-13, all three insurance groups had a higher average MME dose in 2017 than in 2007.

Disabled Medicare beneficiaries were much more likely to use opioids than others. They were also more likely to take higher daily doses over a longer period of time.

For example, they found that 52% of disabled Medicare beneficiaries used opioids annually, compared with 14% of commercially insured people and 26% of aged Medicare Advantage beneficiaries.

Disabled Medicare beneficiaries aged 45 to 54 had the highest rate of opioid use. In the third quarter of 2012, 45% of disabled Medicare beneficiaries aged 45 to 54 used opioids.

They also report that within the commercially insured group, by far the most commonly dispensed drug was hydrocodone, but in terms of volume, oxycodone and hydrocodone were similar.

During the study period, the average daily observed dose for disabled Medicare beneficiaries using opioids never dropped below 50 MME per day, a level at which odds of overdose are up to four times higher than with doses of less than 20 MME per day.

The researchers point out that this is an observational study so cannot establish cause, and they outline some limitations. For example, the study did not capture all groups of people, including uninsured people, and claims data may have missed prescriptions for people with multiple sources of insurance.

Nevertheless, they say their results make clear that opioid use rates are high in the US compared with other countries.

And they suggest that doctors and patients should consider whether long term opioid use is improving the patient's ability to function, and if not, should consider other treatments either as an addition or replacement to opioid use.