Long-term trajectories of low back pain in older men: A prospective cohort study with 10-year analysis of the MrOS Study

While low back pain (LBP) may persist or recur over time, few studies have evaluated the individual course of LBP over a long-term period, particularly among older adults. Based on data from the longitudinal Osteoporotic Fractures in Men (MrOS) study, we aimed to identify and describe different LBP trajectories in older men and characterize members in each trajectory group. A total of 5,976 community-dwelling men (mean age=74.2) enrolled at six US sites were analyzed. Participants self-reported LBP (yes/no) every 4 months during a maximum of 10 years. Latent class growth modelling was performed to identify unique LBP trajectory groups that explained variation in the LBP data. The association of baseline characteristics with trajectory group membership was assessed using univariable and multivariable multinominal logistic regression. A five-class solution was chosen; no/rare LBP (n=2442/40.9%), low frequency-stable LBP (n=1040/17.4%), low frequency-increasing LBP (n=719/12%), moderate frequency-decreasing LBP (n=745/12.5%) and high frequency-stable LBP (n=1030/17.2%). History of falls (OR=1.52), history of LBP (OR=6.37), higher physical impairment (OR=1.51-2.85) and worse psychological function (OR=1.41-1.62) at baseline were all associated with worse LBP trajectory groups in this sample of older men. These findings present an opportunity for targeted interventions and/or management to older men with worse or increasing LBP trajectories and associated modifiable risk factors, to reduce the impact of LBP and improve quality of life.