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Monday, February 4, 2019

Long-Term Prescription Opioid Use in Severe Osteoarthritis Varies by Region

Target Audience and Goal Statement: Rheumatologists, pain specialists, geriatricians, orthopedists, and primary care physicians
The goal was to examine prescription opioid use among Medicare enrollees with severe osteoarthritis who underwent total joint replacements (TJRs).
Questions Addressed:
  • What was the level of opioid use in the year preceding a TJR and overall among Medicare beneficiaries with advanced osteoarthritis and an indication for pain control?
  • Were there any geographical variations in rates of treatment with long-term opioid therapy in osteoarthritis, which was not fully explained by differences in access to healthcare providers, varying case-mix, or state-level policies?
Synopsis and Perspective:
Based on a recent U.S. News & World Report analysis, the opioid crisis is here to stay for years. This epidemic, which is affecting both children and adults, started 40 years ago and grew exponentially in the ensuing decades. The Department of Health and Human Services statedthat “increased prescription of opioid medications led to widespread misuse of both prescription and non-prescription opioids before it became clear that these medications could indeed be highly addictive.”
Many opioid prescriptions in the U.S. are written for osteoarthritis of the hip or knee — a common reason for chronic pain that today affects nearly 30 million U.S. adults. In the earlier stages of the disease, treatment usually involves non-steroidal anti-inflammatory drugs, steroids, and opioid analgesics. Patients with severe pain that is inadequately controlled by medications are usually candidates for TJRs.
Very little was known about real-world long-term use of opioids in older patients with osteoarthritis. Therefore, Rishi J. Desai, PhD, of Harvard Medical School in Boston, and colleagues, set out to conduct “an observational cohort study in a nationwide sample of Medicare enrollees with severe osteoarthritis to describe long-term opioid use and to evaluate the role of geography and healthcare access in d
Medicare beneficiaries (n=358,121; mean age 74) who underwent TJRs for the treatment of osteoarthritis at 4,080 primary care service areas from 2010 to 2014, where opioid use was reported, were included in this study. The main outcome of interest was the percentage of patients on long-term opioid therapy within each area. Desai’s group also evaluated opioid use in the year preceding each TJR procedure. Another variable of interest was opioid use by geographic region. New York was used as the reference state because of a large sample size and consistently low opioid use reported in previous investigations, the authors noted.
Average daily dose was calculated in morphine milligram equivalents (MME). According to a 2016 CDC guideline, caution should be exercised when prescribing opioids at any dosage, but special attention needs to be paid to the benefit-risk profile when the dose is increased to ≥50 MME per day. A decision to titrate dosage up to ≥90 MME should be carefully justified or avoided if possible.
Most of the patients included were women (67.8%) and white (91.9%). Back and neuropathic pain were highly prevalent among all patients. Of these study subjects, 42.3% were short-term opioid users (<90 days), 16.5% were long-term users (≥90 days), and 40.9% were non-users. Opioid consumption among long-term users was relatively stable over a 3-year period (16.8% in 2011 and 2012, 16.6% in 2013, and 16.3% in 2014).
The median length of use in the long-term group was 7 months, compared with 15 days in the short-term group. About 19% of the long-term users and 15.9% of the short-term users consumed more than 50 MME per day. Use of several opioids were higher in long-term compared with short-term users: tramadol (45.8% vs 36.8%, respectively), oxycodone (32.2% vs 21.7%), and fentanyl (6.2% vs 0.5%).
Opioid prescription rates varied across the U.S., with generally higher rates noted in the South compared with the Northeastern and Midwestern regions. The unadjusted mean percentage of long-term opioid users varied widely across states, ranging from 8.9% in Minnesota to 26.4% in Alabama.
Access to rheumatologists was not associated with long-term opioid use. When comparing areas with the highest concentration of primary care services (>8.6 per 1,000 beneficiaries) versus lowest (<3.6 per 1,000), only a modest association was seen between access to primary care physicians and rates of long-term opioid use (adjusted mean difference 1.4%, 95% CI 0.8%-2.0%).
Study limitations included not having data on pain severity or pain-related functioning for patients in this cohort, limited generalizability (TJR use among blacks was 40% lower than among whites), historical data that may not have captured post-2014 shifts in prescription opioid use patterns in this population (in response to the growing awareness about the opioid epidemic), and the fact that no evaluations were performed to see whether TJR changed opioid use in these patients.
Source Reference: Arthritis & Rheumatology, Jan. 28 2019, DOI: 10.1002/art.40834
Study Highlights: Explanation of Findings
Osteoarthritis is one of the most common reasons for chronic pain in the U.S. The current study had several strengths, e.g., comprehensive risk-adjustment based on patient demographics, comorbid conditions, as well as variation in state-level policies. One in six Medicare enrollees with osteoarthritis used long-term prescription opioids (≥90 days) for pain management in the year leading up to a TJR procedure (average duration ~7 months). Some of the long-term users (~20%) fell into the CDC-defined category of high-risk for opioid-related harms because they consumed an average daily dose of ≥50 MME.
Long-term opioid use observed in this study was more than twofold higher than previously reported estimates, according to the authors. Patients with severe osteoarthritis represent a particularly high-risk group, as they have substantially higher rates of long-term prescription opioid use compared to an average Medicare enrollee.
Results from a separate randomized trial did not support the initiation of opioid therapy for moderate to severe chronic back pain or hip or knee osteoarthritis pain. A Cochrane review of opioids for osteoarthritis stated that “for the pain outcome in particular, observed effects were of questionable clinical relevance.” Taken together with current findings, the need for caution in prescribing opioids for patients with severe osteoarthritis is vital and the authors urged that “special emphasis on periodically monitoring prescription opioid use is required to ensure benefits outweigh risks at prescribed doses.”
Geographic variations in opioid prescription practices noted in this study have also been observed by other researchers who were examining separate outcomes. Regional variations could not fully be explained by differences in access to primary care physicians or rheumatologists, variations in patient characteristics, or state-level policies, including medical marijuana and prescription drug monitoring programs. Overall, the results underscored the need for geographically targeted interventions to ensure widespread dissemination and implementation of safe opioid prescribing guidelines to make a meaningful impact on prescribing practices.
The CDC’s guidelines for the responsible prescription of opioids for chronic pain involves key criteria:
  • Use non-opioid therapies, either alone or in combination with opioid therapy, for treatment of chronic pain; and only consider opioid therapy if the benefits for pain are expected to outweigh the risks
  • Start with the lowest effective dosage and short-acting opioids instead of extended-release/long-acting opioids, when using opioids
  • Follow-up visits should include assessments of whether opioids are improving pain and function without causing harm

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