Trajectories of change over time can illustrate the course of pain. Back pain trajectories have previously been identified among adults. Understanding different patterns of back pain among adolescents could shed light on how persistent back pain develops. We aimed to identify and compare trajectories of back pain among adolescents in the general population. This prospective cohort study followed 1,336 adolescents (initially aged 11 years) every three months for three years, using self-completion questionnaires. Latent class growth analysis was used to cluster subjects into distinct trajectories of back pain. Six clusters were identified. Most subjects (78%) had very low likelihood of back pain throughout follow-up. The second largest cluster (10%) had relatively low and falling probability of back pain. Two clusters (4% each) showed increasing probability of back pain. One cluster had a peak likelihood of pain around age 13 (2%). The smallest cluster (1%) had very high probability of back pain throughout follow-up. The more painful trajectories had significantly fewer males, higher levels of depression and somatization, and lower life satisfaction at baseline, but differed little in physical activity or BMI.Background and purpose
Methods and results