Researchers found 4 distinct trajectories for pain and function over up to 12-weeks of exercise interventions in a recent study that aimed to identify these trajectories from exercise interventions in knee osteoarthritis (OA), and to determine their association with baseline factors. These findings will help disentangle the heterogeneity of treatment response and may advance patient-centered care in knee OA. Researchers analyzed a prospective cohort of 171 participants (mean age 61 years; BMI 32 kg/m2; 71% female; 57% white) with symptomatic knee OA from a randomized trial comparing 12-week Tai Chi and physical therapy. They analyzed weekly Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain (0–500) and function (0–1700) scores using group-based trajectory models. They found:
- 4 pain trajectories were identified: Lower-Early Improvement (43%), Moderate-Early Improvement (32%), Higher-Delayed Improvement (15%), and Higher-No Improvement (10%).
- There were similar trajectories for function, except that the lower function trajectories diverged into gradual (12%) or delayed-improvement (15%).
- Compared with the Lower-Early Improvement pain trajectory, moderate and higher trajectories were associated with poorer physical and psychosocial health.
- A similar pattern of associations was found among the function trajectories.
Lee AC, Harvey WF, Han X, et al. Pain and functional trajectories in symptomatic knee osteoarthritis over up to 12 weeks of exercise exposure. Osteoarthritis Cartilage. 2018;26(4):501-512. doi:10.1016/j.joca.2018.01.016.