Inadequate Pain Relief in OA, High Opioid Use Before TKA

Inadequate pain relief was recorded in 68.8% of a sample of people with hip or knee OA who participated in the population-based EpiReumaPt study, researchers reported at the OARSI 2022 World Congress.

“This can be explained by a lack of effectiveness of current management strategies, low uptake of recommended interventions by health care professionals, and also by low adherence by patients to medication and lifestyle interventions,” said Daniela Sofia Albino Costa, MSc, a PhD student at NOVA University Lisbon.

In addition to looking at the prevalence of inadequate pain relief – defined as a score of 5 or higher on the Numeric Pain Rating Scale (NPRS) – the study she presented at the congress, which was sponsored by the Osteoarthritis Research Society International, looked at the predictors for inadequate pain control.

It was found that being female, obesity, and having multimorbidity doubled the risk of inadequate versus adequate pain control, with respective odds ratios of 2.32 (P < .001), 2.26 (P = .006), and 2.07 (P = .001). Overweight was also associated with an increased odds ratio for poor pain control (OR, 1.84; P = .0035).

“We found that patients with inadequate pain relief also have a low performance on activities of daily living and a low quality of life,” Ms. Costa said.

Nearly one-third (29%) of patients in the inadequate pain relief group (n = 765) took medication, versus 15% of patients in the adequate pain relief group (n = 270). This was mostly NSAIDs, but also included analgesics and antipyretics, and in a few cases (4.8% vs. 1.3%), simple opioids.

“We know that current care is not concordant with recommendations,” said Ms. Costa, noting that medication being used as first-line treatment and core nonpharmacologic interventions are being offered to less than half of patients who are eligible.

In addition, the rate for total joint replacement has increased globally, and pain is an important predictor for this.

“So, we need to evaluate pain control and current management offered to people with hip or knee arthritis to identify to identify areas for improvement,” Ms. Costa said.

High rates of prescription opioid use before TKA

In a separate study also presented at the congress, Daniel Rhon, DPT, DSc, director of musculoskeletal research in primary care at Brooke Army Medical Center in San Antonio, gave a worrying glimpse of high rates of opioid use in the 4 years before total knee arthroplasty (TKA).

Using data from the U.S. Military Health System, the records of all individuals who had a knee replacement procedure between January 2017 and December 2018 were studied, to identify and characterize the use of prescription opioids.

Of the 46,362 individuals, 52.9% had prior opioid use, despite the fact that “opioids are not recommended for the management of knee OA,” said Rhon.

He also reported that as many as 40% of those who had at least one prescription for opioids had received a high-potency drug, such as fentanyl or oxycodone. The mean age of participants overall was 65 years, with a higher mean for those receiving opioids than those who did not (68 vs. 61.5 years). Data on sex and ethnicity were not available in time for presentation at the congress.

“Most of these individuals are getting these opioid prescriptions probably within 6 months, which maybe aligns with escalation of pain and maybe the decision to have that knee replacement,” Rhon said. Individuals that used opioids filled their most recent prescription a median of 146 days before TKA to surgery, with a mean of 317 days.

“You can’t always link the reason for the opioid prescription, that’s not really clear in the database,” he admitted; however, an analysis was performed to check if other surgeries had been performed that may have warranted the opioid treatment. The results revealed that very few of the opioid users (4%-7%) had undergone another type of surgical procedure.

“So, we feel a little bit better, that these findings weren’t for other surgical procedures,” said Rhon. He added that future qualitative research was needed to understand why health care professionals were prescribing opioids, and why patients felt like they needed them.

“That’s bad,” Haxby Abbott, PhD, DPT, a research professor at the University of Otago, Dunedin, New Zealand, commented on Twitter.

Abbott, who was not involved in the study, added: “We’ve done a similar study of the whole NZ population [currently under review] – similar to Australia and not nearly as bad as you found. That needs urgent attention.”

Sharp rise in opioid use 2 years before TKA

Lower rates of opioid use before TKA were seen in two European cohorts, at 43% in England and 33% in Sweden, as reported by Clara Hellberg, PhD, MD, of Lund (Sweden) University. However, rates had increased over a 10-year study period from a respective 23% and 16%, with a sharp increase in use in the 2 years before knee replacement.

The analysis was based on 49,043 patients from the English national database Clinical Practice Research Datalink, and 5,955 patients from the Swedish Skåne Healthcare register who had undergone total knee replacement between 2015 and 2019 and were matched by age, sex and general practice to individuals not undergoing knee replacement.

The prevalence ratio for using opioids over a 10-year period increased from 1.6 to 2.7 in England, and from 1.6 to 2.6 in Sweden.

“While the overall prevalence of opioid use was higher in England, the majority of both cases and controls were using weak opioids,” Hellberg said.

“Codeine was classified as a weak opioid, whereas morphine was classified as a strong opioid,” she added.

In contrast, the proportion of people using strong opioids in Sweden was greater than in England, she said.

The high opioid use found in the study highlights “the need for better opioid stewardship, and the availability of acceptable, effective alternatives,” Hellberg and associates concluded in their abstract.

The study presented by Ms. Costa was funded by the Portuguese national funding agency for science, research and technology and by an independent research grant from Pfizer. Rhon acknowledged grant funding from the National Institutes of Health and the U.S. Department of Defense. Hellberg had no conflicts of interest to disclose.

This story originally appeared on MDedge.com, part of the Medscape Professional Network.

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