Although opioid use is common among older patients with osteoarthritis, rates of long-term opioid use differed significantly from state to state, with the lowest rates reported in Minnesota and the highest rates in Alabama, according to findings in Arthritis & Rheumatology.
“Osteoarthritis of hip or knee is one of the most common reasons for chronic pain in the U.S., affecting nearly 30 million U.S. adults and the prevalence is expected to rise with aging of the population,” Rishi J. Desai, MS, PhD, of Brigham and Women’s Hospital, and colleagues wrote. “Although two previous studies have investigated the cross-sectional prevalence of prescription opioid use in osteoarthritis patients, neither of them studied long-term use.”
To analyze the rates of long-term opioid use among patients with OA based on health care access and geography, Desai and colleagues conducted an observational cohort study using Medicare data from 2010 to 2014. Focusing on 358,121 patients — with a mean age of 74 years — with advanced OA undergoing total joint replacement surgery, the researchers assessed state of residence, as well as health care access, defining each primary care service area based on the number of rheumatologists per 1,000 Medicare beneficiaries.
Although opioid use is common among older patients with OA, rates of long-term opioid use differed significantly from state to state, with the lowest rates reported in Minnesota and the highest rates in Alabama, according to findings.
The primary outcome was the percentage of patients with OA using opioids long-term — defined as 90 day or more during the 360-day period immediately prior to total joint replacement — within each primary care service area. Desai and colleagues used a multilevel generalized linear regression model adjusting for casemix at the primary-care-service-area level, as well as policies including rigor of prescription drug monitoring programs and legalized medical marijuana at the state level.
According to the researchers, one in six patients used long-term opioids for pain in the year leading up to total joint replacement. However, the unadjusted mean percentage of users varied greatly across states, ranging from 8.9% in Minnesota to 26.4% in Alabama.
“The high use of long-term prescription opioids for chronic pain we observed in this study is particularly striking because their effectiveness is questionable in chronic noncancer pain, and the evidence of harm is substantial,” Desai told Healio Rheumatology.
This variation remained in adjusted models. In addition, access of primary care physicians was “only modestly” associated with rates of long-term opioid treatment (mean adjusted difference between primary care service areas = 1.4%; 95% CI, 0.8-2). Access to a rheumatologist was not associated at all with long-term opioid treatment.
“The variation was staggering between the lowest and highest regions and persisted even after adjusting for varying case-mix and health care access across states,” Desai said. “This means some of the high use is modifiable if we design targeted interventions for physicians caring for these patients in specific geographical areas, to promote safe use of prescription opioids in older adults suffering from chronic pain due to hip or knee osteoarthritis.” – by Jason Laday
Disclosure: Desai reports research grants to Brigham and Woman’s Hospital from Merck and Vertex. Please see the study for all other authors’ relevant financial disclosures.