Psychological factors contribute more to chronic low back pain than spine pathology: An LLM-based analysis of radiology reports.

BACKGROUND: Chronic low back pain (cLBP) is the leading global cause of disability, yet anatomical, psychological, and socioeconomic determinants are typically studied in isolation, with limited large-scale integration of imaging and biopsychosocial data. We linked imaging findings with demographic, anthropometric, and biopsychosocial characteristics to determine their relative contributions to cLBP. METHODS: We retrospectively analyzed 1,480 Chicago-based patients with lumbar spine MRI between 3/2014 and 3/2024. cLBP was as two or more LBP diagnoses recorded six months apart. Spinal pathologies (stenosis, disc disease, facet arthropathy and spondylolisthesis) were extracted from radiology reports using a large language model (GPT-4) and benchmarked against a regex (rule-based text search) pipeline. Multivariable logistic regression evaluated associations between cLBP diagnosis and demographic, anthropometric, socioeconomic, psychological, and anatomical determinants. A parallel linear regression modeled overall anatomical pathology burden. RESULTS: The LLM pipeline achieved an F1-score of 0.98 versus 0.92 for regex. cLBP diagnosis was most strongly associated with depression (OR=2.69, p<0.001) and anxiety (OR=2.31, p<0.001), with smaller contributions from spinal stenosis (OR=1.07, p=0.006) and spondylolisthesis (OR=1.15, p=0.039). Leave-one-domain-out analysis showed psychological factors were most impactful (ΔAIC=120.1), followed by anatomical (ΔAIC=37.0), demographic/anthropometric (ΔAIC=21.8), and socioeconomic (ΔAIC=3.0). Overall anatomical burden was associated with age, male sex, higher BMI, and Non-Hispanic White race, with no associations with socioeconomic or psychological variables. CONCLUSIONS: Factors associated with diagnosed cLBP and those associated with structural spinal pathology are largely dissociated. Psychological comorbidities show the strongest associations with cLBP, while anatomical burden is mostly driven by demographics, reinforcing the psychosocial nature of cLBP.