Opioid Use Among Medicare Beneficiaries With Knee Osteoarthritis: Prevalence and Correlates of Chronic Use

To determine the prevalence of chronic and occasional opioid use and identify risk factors of opioid use among persons with knee osteoarthritis (OA).

We used the Medicare Current Beneficiary Survey to select a knee OA cohort. We obtained data on demographics characteristics, marital status, comorbidities, insurance, and prescription medication coverage from survey data and linked Medicare claims. We included all prescribed medication records classified as opioid under the First Databank therapeutic antiarthritics or analgesics categories. We stratified individuals with knee OA into 3 opioid use groups: 1) nonusers (0 prescriptions/year), 2) occasional users (1-5 prescriptions/year), and 3) chronic users (6+ prescriptions/year). We built multivariable logistic regression models using a generalized estimating equation to determine correlates of chronic opioid use.

Among 3,549 Medicare beneficiaries with knee OA and a mean ± SD age of 78 ± 7 years, 68% were female, 9% were chronic users, and 21% used opioids occasionally. Multivariable analysis showed that non-Hispanic ethnicity (odds ratio [OR] 4.8, 95% confidence interval [95% CI] 2.2-10.2), divorced status (vs. married; OR 2.3, 95% CI 1.5-3.5), Medicaid eligibility (OR 1.9, 95% CI 1.3-2.7), depression (OR 1.9, 95% CI 1.5-2.5), chronic obstructive pulmonary disease (OR 1.9, 95% CI 1.4-2.5), and inability to walk without assistive devices (vs. no difficulty walking; OR 2.4, 95% CI 1.5-3.7) were independently associated with chronic opioid use.

A total of 9% of persons with knee OA use opioids chronically. Efforts to find nonopioid regimens for treating knee OA pain should be tailored to patients at high risk for chronic use.