Opioid prescribing doubled over a quarter of a century – but there’s a critical evidence gap outside the US, researchers warn
Research led by the University of Sydney has found that the number of people with chronic non-cancer pain prescribed an opioid medicine worldwide increased significantly between 1991 and 2015.
The systematic review of studies from across the world is the first to examine the literature about the extent opioid pain relievers are being prescribed to manage people with chronic pain conditions.
The research spanned eight countries and evaluated 42 published studies that included 5,059,098 people with chronic pain conditions (other than cancer).
Two-thirds of the studies were from the US; only one study was from Australia and the other studies were from the United Kingdom, Norway, India, Spain, Denmark and Canada.
The researchers found that in people with chronic, non-cancer pain, opioid prescribing rose from around 20% in the early years from 1991 to around 40% in the later years examined.
On average over this period approximately one in three patients (30.7%) were prescribed an opioid medicine.
This included 42% of people with chronic lower back pain.
As for types of opioid analgesic, the analysis included weak opioids such as codeine, or strong opioids such as oxycodone.
The 17 studies that described the type of opioid pain relief prescribed showed that 24.1% of opioids prescribed were strong combinations (such as oxycodone and paracetamol); 18.4% were strong opioids (such as oxycodone, morphine or fentanyl); 8.5% were weak opioids, such as codeine or tramadol; and 11% were weak combinations.
“Over this period, on average around 30% of people with chronic pain were prescribed an opioid medicine,” said lead author Dr Stephanie Mathieson, from the School of Public Health in the Faculty of Medicine and Health.
“We noted that a higher proportion of people were prescribed a strong opioid medicine such as oxycodone compared to weak opioid pain-relieving medicines.”
The authors also looked at gaps in data examining trends in opioid prescribing around the world.
“The prescription of opioids across the globe differs,” they wrote.
“The high-income WHO regions of North America, Europe (western and central) and Oceania account for 95.7% of global opioid use but only represents approximately 15% of the world’s population.
“We found from our studies that the prescription of opioids for chronic non-cancer pain is more commonly reported in these regions, but no studies compared data from multiple countries.
“However, there is some uncertainty as only 11 of the 42 studies were from countries other than North America.
“Although our results show that opioids are being increasingly prescribed for chronic non-cancer pain over time, this is at odds with the pattern of general opioid use in some countries. For instance, reports from Scandinavian countries suggest stable opioid dispensing in Demark, Sweden and Norway between 2006 and 2014, whereas in the UK, the prescribing of opioids in general practice doubled between 2000 and 2012 then began to decline from 2016 to 2017.
“In the USA following reports in 2017 that the prescription of opioids is now a contributor to reduced life expectancy in the USA and their life expectancy is lower than most high-income countries, opioid mitigation strategies may have reduced opioid prescribing.”
They concluded that, “Opioid prescribing for patients with chronic non-cancer pain is common and has increased over time, with stronger opioids more frequently prescribed than weaker opioids”.