Frailty predicts knee pain trajectory over 9 years and may be a treatment target for knee pain, according to a study published in Pain Medicine.
Osteoarthritis (OA) responds better to early prevention and treatment, so identifying patients at higher risk of progressing to severe pain is important. Frailty may be a risk factor for the development of OA, which suggests it could contribute to pain progression and be a treatment target. With this in mind, researchers aimed to identify pain trajectories in a large prospective cohort study and to describe the role of frailty at baseline to predict pain trajectories over 9 years. A total of 4419 participants (58% women) with a mean age of 61.3 years were included from the OA Initiative (OAI) cohort. Knee pain in both knees at baseline between February 2004 and May 2006 and the annual follow-up visits over 9 years was assessed. Frailty was assessed using the frailty phenotype criteria.
Baseline characteristics show that 38.4% of the participants were not frail, 55.4% were prefrail, and 6.3% were frail. Those who were prefrail and frail were more likely to be older, women, Black or African American, have a higher body mass index, have more severe knee pain, have radiographic OA, have more comorbidities, and take more pain-relief medication. Participants who were prefrail or frail had a higher likelihood of experiencing more intense pain patterns (with odds ratios ranging from 1.5 to 5.0) in both univariable and multivariable analyses compared with those who did not exhibit any frailty. A significant dose-response relationship between frailty severity and more severe pain trajectories was found. Frailty components such as exhaustion, slow gait speed, and weak energy were associated with severe pain, with odds ratios ranging from 1.5 to 2.2. Conversely, low physical activity reduced the risk of moderate or severe pain, with an odds ratio of 0.7 (95% CI, 0.6-0.9).
Study limitations include the inability to determine whether weight loss as a component of frailty was unintentional or not and may have overestimated frailty and prefrailty prevalence. Additionally, weak energy was assessed based on 1 item from the 12-item short-form health survey rather than grip strength, which may have led to misclassification.
Researchers concluded, “Our findings showed that, compared to participants without frailty, those with either frailty or pre-frailty were more likely to have more severe pain trajectories, even after controlling for knee pain at baseline.”
This article originally appeared on Clinical Pain Advisor
Cai G, Zhang Y, Wang Y, et al. Frailty predicts knee pain trajectory over 9 years: results from the Osteoarthritis Initiative. Pain Med. Published online July 10, 2023. doi:10.1093/pm/pnad097