The following is a summary of “Quantifying sustained pain worsening in knee osteoarthritis,” published in the June 2023 issue of Osteoarthritis and Cartilage by Collins et al.
According to recent research, many individuals with knee osteoarthritis (OA) have stable symptoms. More research must be done on the duration and occurrence of patient symptom exacerbations or flares that disturb this stable course. They aim to describe the frequency and length of pain-worsening episodes in knee OA patients. Researchers chose Osteoarthritis Initiative participants with radiological, symptomatic knee OA. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain increased by at least nine points to qualify as a clinically significant increase in knee pain. A chronic deterioration was defined as keeping at least 80% of the initial increase. To calculate the incidence rate (IR) of bouts of worsening pain, investigators employed Poisson regression.
The analysis included 1,093 people. WOMAC pain increased by 1 point in 88% of the population (IR: 26.3 per 100 person-years (95% CI: 25.2, 27.4)). Only 1 episode of substantial deterioration occurred in 48% of cases (IR: 9.7 per 100 person-years, 95% CI: 8.9, 10.5). After the initial rise, elevated discomfort persisted for an average of 2.4 years.
Fewer than half of the participants with knee OA experienced a worsening episode of prolonged pain. However, most participants with knee OA reported at least one clinically meaningful rise in WOMAC discomfort. These individual-level data show that the course of OA pain is more complex and variable than predicted by trajectory studies. These findings help people with symptomatic knee OA make decisions about prognosis and treatment options together.