Concerns have been raised about the proportion of people who are hooked on opioid pain killers, after a large new analysis suggested that many people who take the drugs could become addicted.

The new study suggests that almost one in ten people who start a long-term course of pain medication which contains opioids can become dependent on the drugs.

And up to one in three display behaviours of addiction.

Prescription drugs which contain opioids include tramadol, codeine, oxycodone, morphine, methadone and fentanyl, among others.

The new study, led by academics from the University of Bristol and published in the journal Addiction, examined data from 148 studies involving more than 4.3 million patients aged 12 and over.

The researchers looked at information on people with chronic pain who had been treated with “opioid analgesics” for at least three months.

Overall the research team found that 9.3% of patients given pain medication containing opioids had “dependence and opioid use dependence disorder”.

Some 29.6% displayed “signs and symptoms” of dependence.

One in five people (22%) displayed signs of “aberrant behaviour” including seeking early refills, repeated dose escalations or frequently lost prescriptions.

“Problematic pharmaceutical opioid use appears to be common in chronic pain patients treated with opioid analgesics,” the authors wrote in the journal Addiction.

Misuse of prescription opioid drugs in the US has been described as a “crisis” and declared a public health emergency.

Researchers said that in the UK there has been “increasing concern” about opioid use because of the “widespread prescribing” for chronic non-cancer pain and the increase in opioid-related deaths.

According to official figures, some 5.6 million adults in England were given a prescription for one or more opioid pain medicines in 2017/18 – though at the time figures were falling.

Lead author Kyla Thomas, professor of public health medicine at the University of Bristol, told the PA news agency: “The issue in the UK has not been as bad as the US, but we can see how prescription opioids caused a real problem there.

“And actually, the prescribing of opioids in this country was really quite high as well and until 2018 was increasing, until measures started to be taken by NHS England encouraging GPs not to use opioids to manage people with chronic non-cancer pain.

“There has been work to continue to cut down opioid prescriptions.”

She said prescriptions have been cut by almost half a million between 2018 and 2022/23 but added: “There is more work to be done.

There are an enormous amount of people who are being prescribed opioids for long-term pain when opioids are not really very effective for long-term pain.

“Opioids are effective if you have acute pain, so short pay-term pain like after surgery, or if you’ve kind of been in an accident or something, and in palliative care.

“But opioids are not useful for people with long-term pain, and they’re still used too much, so much more than they should be used, by GPs in the UK.

“There is a lot of work happening in the background to reduce this. But the problem hasn’t been completely sorted out. As yet, it will continue to take more effort.”

A Department of Health and Social Care spokesperson said: “Clinicians should work with their patients to decide on the best course of treatment, ensuring it is appropriate and that they take account of national guidance on the treatment’s effectiveness.

“NHS England has an action plan to help local healthcare providers reduce inappropriate prescribing of high strength painkillers and other addiction-causing medicines, while we are committed to ensuring people who misuse substances get the support they need.”