Analgesic utilization in people with knee osteoarthritis: A population-based study using primary care data

Area of Science:

• Pharmacology
• Epidemiology
• Rheumatology

Background:

• Osteoarthritis (OA) is a prevalent chronic painful condition affecting major joints like the knee.
• Current treatment guidelines for OA pain include paracetamol, NSAIDs, and opioids.
• Antidepressants and anti-epileptic drugs (AEDs) are frequently used off-label for chronic non-cancer pain, including OA.

Purpose of the Study:

• To describe analgesic utilization patterns in patients with knee OA at a population level.
• To analyze trends in the prescription of various analgesic classes over a 15-year period.

Main Methods:

• A cross-sectional study utilizing data from the U.K. Clinical Practice Research Datalink (CPRD) from 2000 to 2014.
• Examined the use of antidepressants, AEDs, opioids, NSAIDs, and paracetamol in adults with knee OA.
• Measured annual prescriptions, defined daily doses (DDD), and oral morphine equivalent dose (OMEQ).

Main Results:

• Over 8.9 million prescriptions were issued to 117,637 knee OA patients.
• Prescribing of all drug classes, except NSAIDs, steadily increased from 2000 to 2014.
• Opioids were the most prevalent class, with tramadol being the most common. AED prescribing saw the largest relative increase, rising from 2 to 11 per 1000 registrants.

Conclusions:

• Overall analgesic prescribing, excluding NSAIDs, increased for knee OA patients.
• Opioids remained the most frequently prescribed analgesic class.
• Anti-epileptic drugs demonstrated the most significant growth in prescribing during the study period.