Osteoarthritis (OA) of the knee is a painful condition affecting ∼13% of persons ages >65 years. We sought to examine whether the use of opioids in older persons with OA has increased over the past decade and what patient characteristics may correlate with their use.
We assembled national cohorts of individuals with knee OA using data from the 2003, 2006, and 2009 waves of the Medicare Current Beneficiary Survey. The survey data contained information on demographics, health status, and prescribed medications linked to Medicare claims. We used multivariate logistic regression to establish whether opioid use changed over time and to identify factors associated with greater opioid use. The outcome was defined as receiving ≥1 opioid prescription in the study year.
The mean age and sex were similar across years (77 years and 69% women, respectively). There was a significant increase in opioid prescribing between 2003 and 2009, with 31% of patients receiving opioids in 2003, 39% in 2006, and 40% in 2009 (odds ratio [OR] 1.5, 95% confidence interval [95% CI] 1.1-2.0 for 2006 and 2009 compared with 2003). Independent correlates of opioid use across time periods included female sex (OR 1.5, 95% CI 1.2-2.0), functional limitation (OR 2.1, 95% CI 1.6-2.7), poor self-reported health status (OR 1.6, 95% CI 1.2-2.0), chronic obstructive pulmonary disease (OR 1.4, 95% CI 1.0-1.8), and musculoskeletal disease besides OA (OR 1.9, 95% CI 1.2-2.8).
As the prevalence and incidence of knee OA continues to increase, the public health impact of greater opioid use should be monitored carefully.