Long-Term Prognosis and Risk Factors for Low Back Pain-Related Disorders in the General Population: A 7-Year...

Low back pain (LBP) is a leading cause of disability worldwide, particularly in aging populations. While the Oswestry Disability Index (ODI) is widely used to assess LBP-related disability, few studies have evaluated its long-term trajectory and predictive factors in general populations.

This 7-year longitudinal study included 553 community-dwelling adults (mean age 66.3 years) from the Wakayama Spine Study, a population-based sub-cohort of the Research on Osteoarthritis/Osteoporosis against Disability (ROAD) study. Participants completed whole-spine magnetic resonance imaging and responded to the ODI questionnaire at baseline and follow-up. Disability levels were classified as mild (0%-20%), moderate (21%-40%), or severe (41%-60%). Longitudinal transitions in disability categories were analyzed descriptively. Multiple linear regression was used to identify predictors of ODI deterioration.

The mean ODI score significantly increased from 9.6±11.5 at baseline to 12.2±14.2 after 7 years (p<0.001), although the change did not reach clinical significance. Among participants initially classified as mildly disabled (n=468), 88.0% remained stable, while 12.0% worsened. Of those with moderate disability (n=73), 35.6% improved, 44.0% remained unchanged, and 20.5% worsened. No participant with severe disability (n=40) improved to mild. Female sex, older age, higher body mass index, and vertebral fractures (semiquantitative grade ≥2) were significant predictors of worsening disability (p<0.05). Higher baseline ODI was inversely associated with deterioration.

In this population-based cohort, LBP-related disability modestly worsened over 7 years. Older adults, women, individuals with obesity, and those with vertebral fractures were at greatest risk. These findings support early intervention and screening strategies to prevent disability progression in at-risk populations.