By Pat Anson

Over the years, hundreds of studies have been conducted to determine how common it is for a pain patient on long-term opioid therapy to become addicted. Estimates range from less than 1% to more than 80% of patients developing opioid use disorder (OUD), also known as problematic pharmaceutical opioid use (POU).

The wide variation in estimates is largely due to conflicting definitions, terminology, study design and biases. Is a patient misusing or abusing prescription opioids? Do they show signs of dependence or withdrawal? It literally depends which study you read.

New research that tries to settle the matter may have only muddied the water further.

A team of researchers at the University of Bristol conducted a meta-analysis of 148 clinical studies involving over 4.3 million patients in North America and the UK who were treated with opioids for chronic non-cancer pain. The 148 studies were all that was left from nearly 5,300 that were initially screened and rejected for various reasons — which should tell you a lot about the quality of studies that are out there.

“Clinicians and policy makers need a more accurate estimate of the prevalence of problematic opioid use in pain patients so that they can gauge the true extent of the problem, change prescribing guidance if necessary, and develop and implement effective interventions to manage the problem.  Knowing the size of the problem is a necessary step to managing it,” said lead author Kyla Thomas, PhD, Professor of Public Health Medicine at the University of Bristol.

Thomas and her colleagues included studies in their review that reported any sign of POU, such as abuse, tolerance, addiction, dependence, misuse, substance use disorder or “aberrant behavior.” The latter includes seemingly benign behavior like a patient being poorly dressed or unkempt in appearance, canceling or missing an appointment, asking for a specific drug, or even just complaining about their pain.

In some studies, “misuse” was defined so broadly that it included patients who stopped using opioids because their pain went away or they took a pill less often than recommended. A patient like that might be suspected of hoarding or even selling their unused medication.     

In other words, the researchers cast a pretty wide net on what constitutes OUD. And they hauled in a lot of fish.

Their findings, recently published in the journal Addiction, estimate that nearly one in ten pain patients (9.3%) are dependent on opioids and have OUD.

Nearly a third (29.6%) have “signs and symptoms” of dependence and OUD, and over one in five (22%) displayed aberrant behavior.

“Prescription painkiller misuse and addiction are widespread in chronic pain patients” is how the University of Bristol trumpeted the results in a press release, with the lone caveat that “these findings should be interpreted with caution.”

‘OUD Is Everywhere’

Critics of the study were quick to point out that equating dependence with opioid use disorder is misleading at best – the equivalent of a diabetic dependent on insulin being labeled with “insulin use disorder.”

“This is just one more paper, one of zillions, that seizes upon some outcome measures that have poor or no basis in science and that are not in any way indicative of addiction,” says Stephen Nadeau, MD, Professor of Neurology at the University of Florida College of Medicine. “As is so common, it favors the ridiculous notion that OUD is everywhere.”

Nadeau says any patient on daily opioids will experience symptoms of dependence or withdrawal if their medication is suddenly stopped. Neither is a clear sign of addiction or substance use problem, just as a patient asking for a higher dose is not necessarily a symptom of OUD.

“There is never any recognition of the ubiquitous phenomenon of pseudo-addiction: a patient in desperate pain asks for an increase in dosage. Instead of the request being interpreted at face value, the patient is branded with the diagnosis of OUD and booted from the clinic,” Nadeau told PNN.

Being “branded” or stigmatized is something that chronic pain patients like Brett Bradford are all too familiar with. He thinks the new addiction study will only result in more patients being taken off opioids.

“All physicians coming out of med school are being taught these hyper anti-opioid policies. This is only going to fuel things to get worse,” said Bradford. “This madness will not stop until opiates are totally off the market and nobody will be able to get any pain meds for any reason, short of being on their death bed. Maybe. If they are lucky.”