Trends in prescription of opioids from 2003-2009 in persons with knee osteoarthritis.

Symptomatic knee osteoarthritis (OA) affects more than 9.3 million US adults and is a leading cause of disability (1). Increased age and obesity strongly correlate with greater risk of developing OA (2, 3). Because there are no disease modifying regimens currently available, treatments for knee OA focus on symptom relief and functional restoration, and include: exercise, weight reduction, over-the-counter drugs (OTCs), injections, assistive devices, prescription NSAIDS, opioids and possibly total knee replacement (TKR) (4). Persons with symptomatic knee OA live on average 26 years from OA diagnosis, highlighting the importance of long term pain management (5). The choices for effective pain management are guided by patient characteristics and treatment guidelines. The American Academy of Orthopedic Surgeons (AAOS), the American College of Rheumatology (ACR), and the European League Against Rheumatism (EULAR), do not provide strong recommendations for or against the use of opioids in the treatment of OA, while other organizations, including the Osteoarthritis Research Society International (OARSI), the American Geriatrics Society (AGS), and the American Pain Society (APS), give limited guidance on how and when opioids might be best used (6–11). A growing body of research has raised awareness of the adverse effects of non-steroidal anti-inflammatory drug (NSAIDs) use, especially among persons with multiple comorbidities. Concerns regarding the increased risk of cardiac adverse events with COX-2 inhibitors led to warnings and, in 2004, the voluntary withdrawal from the market of rofecoxib (Vioxx), a commonly prescribed COX-2 inhibitor (12–14). As questions surrounding the adverse effects of NSAIDs and COX-2 inhibitors for the treatment of persistent pain related to osteoarthritis have multiplied in the past several years, the use of opiates has emerged as a treatment option that may provide effective pain relief with less risk than NSAIDs. Even as opiates have emerged as reasonable agents for select patients with symptomatic OA who are unresponsive to NSAIDs or at high risk of NSAID toxicity, several trends have highlighted the potential harms of increasing opiate use, at the individual and societal levels. A growing body of controlled trials has documented that opiate use is associated with a range of toxicities including nausea, vomiting, constipation and somnolence, among others, while additional research documents associations between opiate use and fractures, cardiovascular events and death (15–17). In addition, prescription opiates are now the leading source of illicit drug use in the US, costing over 50 billion dollars annually in lost productivity, criminal justice costs, drug abuse treatment and medical complications (18–20). Thus trends in opiate use are relevant both to the challenge of managing chronic pain and to the growing national policy problem of illicit use of prescription opiates. In view of these pressing clinical and policy problems, we sought to examine the temporal trends in opioid prescriptions in elderly persons with knee OA using national survey of Medicare beneficiaries and to identify factors associated with greater opioids prescription in this population.