The bidirectional relationship between chronic joint pain and frailty: data from the Investigating Musculoskeletal Health and Wellbeing cohort

BackgroundPain and frailty are associated, but this relationship is insufficiently understood. We aimed to test whether there is a unidirectional or bidirectional relationship between joint pain and frailty.MethodsData were from Investigating Musculoskeletal Health and Wellbeing, a UK-based cohort. Average joint pain severity over the previous month was assessed using an 11-point numerical rating scale (NRS). Frailty was classified as present/absent using the FRAIL questionnaire. Multivariable regression assessed the association between joint pain and frailty, adjusted for age, sex, and BMI class. Two-wave cross-lagged path modelling permitted simultaneous exploration of plausible causal pathways between pain intensity and frailty at baseline and 1-year. Transitions were assessed using t-tests.ResultsOne thousand one hundred seventy-nine participants were studied, 53% female, with a median age of 73 (range 60 to 95) years. FRAIL classified 176 (15%) participants as frail at baseline. Mean (SD) baseline pain score was 5.2 (2.5). Pain NRS >= 4 was observed in 172 (99%) of frail participants.Pain severity was associated with frailty at baseline (aOR 1.72 (95%CI 1.56 to 1.92)). In cross-lagged path analysis, higher baseline pain predicted 1-year frailty [beta = 0.25, (95%CI 0.14 to 0.36), p < 0.001] and baseline frailty predicted higher 1-year pain [beta = 0.06, (95%CI 0.003 to 0.11), p = 0.040]. Participants transitioning to frailty over one year had higher mean pain scores (6.4 (95%CI 5.8 to 7.1)) at baseline than those who remained non-frail (4.7 (95%CI 4.5 to 4.8)), p < 0.001.ConclusionsThe bidirectional relationship between pain and frailty could lead to a vicious cycle in which each accelerates the other's progression. This justifies attempts to prevent frailty by addressing pain and to include pain measures as an outcome in frailty studies.

Automated summary

A bidirectional relationship exists between joint pain and frailty, with each potentially accelerating the progression of the other. Therefore, addressing pain is crucial in preventing frailty, and including pain measures as an outcome in frailty studies is justified.