Clinical Usefulness of X-Ray Findings for Non-specific Low Back Pain in Korean Farmers: FARM Study

OBJECTIVE: To elucidate the association between non-specific low back pain (NSLBP) and spinal X-ray findings in Korean farmers: Farmers' Cohort for Agricultural Work-Related Musculoskeletal disorders (FARM) study. METHODS: A total of 835 farmers (391 males, 444 females; mean age, 56.6±7.4 years) without red-flag signs of specific LBP were recruited. Presence of LBP more than one week or once a month with more than moderate degree of pain severity during the last year was assessed with a binary questionnaire (yes or no). Spinal degenerative changes were classified into disc height change (DHC) of L4-5 and L5-S1 (grade 0–5) and osteophyte formation of L5 (grade 0–5) by a radiologist based on X-ray findings. Additionally, spondylolisthesis, scoliosis and spondylolysis were assessed. RESULTS: General prevalence of NSLBP was 40.7%, revealing a higher incidence of NSLBP in female and younger farmers compared to male and older farmers (χ(2)=23.3, p<0.001; χ(2)=4.54, p<05, respectively). Among X-ray findings, DHC (L5–S1) grade 4 revealed significantly higher relative risk of NSLBP compared to grade 0 (odds ratio, 5.00; 95% confidence interval, 2.05–12.20) after adjusting age and sex, while other X-ray findings were not associated with NSLBP. CONCLUSION: The NSLBP of Korean farmers was significantly related to lumbar disc degenerative changes, suggesting clinical usefulness of X-ray findings in assessing LBP in farmers.